diff --git a/src/edt/edt/edtMainService.cc b/src/edt/edt/edtMainService.cc
index b678b1b62..b1f4b2df5 100644
--- a/src/edt/edt/edtMainService.cc
+++ b/src/edt/edt/edtMainService.cc
@@ -427,7 +427,9 @@ MainService::cm_flatten_insts ()
 
   view ()->cancel_edits ();
 
-  manager ()->transaction (tl::to_string (tr ("Flatten instances")));
+  if (manager ()) {
+    manager ()->transaction (tl::to_string (tr ("Flatten instances")));
+  }
 
   std::set<db::Layout *> needs_cleanup;
 
@@ -470,7 +472,9 @@ MainService::cm_flatten_insts ()
   //  The selection is no longer valid
   view ()->clear_selection ();
 
-  manager ()->commit ();
+  if (manager ()) {
+    manager ()->commit ();
+  }
 }
 
 void  
@@ -479,7 +483,9 @@ MainService::cm_move_hier_up ()
   view ()->cancel_edits ();
   check_no_guiding_shapes ();
 
-  manager ()->transaction (tl::to_string (tr ("Move up in hierarchy")));
+  if (manager ()) {
+    manager ()->transaction (tl::to_string (tr ("Move up in hierarchy")));
+  }
 
   std::vector<edt::Service *> edt_services = view ()->get_plugins <edt::Service> ();
   for (std::vector<edt::Service *>::const_iterator es = edt_services.begin (); es != edt_services.end (); ++es) {
@@ -529,7 +535,9 @@ MainService::cm_move_hier_up ()
 
   }
 
-  manager ()->commit ();
+  if (manager ()) {
+    manager ()->commit ();
+  }
 }
 
 /**
@@ -735,7 +743,9 @@ MainService::cm_make_cell_variants ()
 
   view ()->cancel_edits ();
 
-  manager ()->transaction (tl::to_string (tr ("Make cell variants for selection")));
+  if (manager ()) {
+    manager ()->transaction (tl::to_string (tr ("Make cell variants for selection")));
+  }
 
   std::vector<lay::ObjectInstPath> new_selection;
   for (std::vector<edt::Service *>::const_iterator es = edt_services.begin (); es != edt_services.end (); ++es) {
@@ -906,7 +916,9 @@ MainService::cm_make_cell_variants ()
     i0 += n;
   }
 
-  manager ()->commit ();
+  if (manager ()) {
+    manager ()->commit ();
+  }
 }
 
 void  
@@ -947,7 +959,9 @@ MainService::cm_resolve_arefs ()
 
   std::vector<lay::ObjectInstPath> new_selection;
 
-  manager ()->transaction (tl::to_string (tr ("Resolve array references")));
+  if (manager ()) {
+    manager ()->transaction (tl::to_string (tr ("Resolve array references")));
+  }
 
   for (std::vector<lay::ObjectInstPath>::const_iterator p = insts_to_resolve.begin (); p != insts_to_resolve.end (); ++p) {
 
@@ -986,7 +1000,9 @@ MainService::cm_resolve_arefs ()
 
   inst_service->set_selection (new_selection.begin (), new_selection.end ());
 
-  manager ()->commit ();
+  if (manager ()) {
+    manager ()->commit ();
+  }
 }
 
 void  
@@ -1041,7 +1057,9 @@ MainService::cm_make_cell ()
 
     view ()->cancel_edits ();
 
-    manager ()->transaction (tl::to_string (tr ("Make cell from selection")));
+    if (manager ()) {
+      manager ()->transaction (tl::to_string (tr ("Make cell from selection")));
+    }
 
     db::cell_index_type target_ci = cv->layout ().add_cell (m_make_cell_name.c_str ());
     //  create target cell
@@ -1090,7 +1108,9 @@ MainService::cm_make_cell ()
 
     }
 
-    manager ()->commit ();
+    if (manager ()) {
+      manager ()->commit ();
+    }
 
   }
 
@@ -1106,7 +1126,9 @@ MainService::cm_convert_to_cell ()
 
   try {
 
-    manager ()->transaction (tl::to_string (tr ("Convert to static cell")));
+    if (manager ()) {
+      manager ()->transaction (tl::to_string (tr ("Convert to static cell")));
+    }
 
     std::vector<edt::Service *> edt_services = view ()->get_plugins <edt::Service> ();
 
@@ -1158,10 +1180,14 @@ MainService::cm_convert_to_cell ()
     //  The selection might no longer be valid
     view ()->clear_selection ();
 
-    manager ()->commit ();
+    if (manager ()) {
+      manager ()->commit ();
+    }
 
   } catch (...) {
-    manager ()->commit ();
+    if (manager ()) {
+      manager ()->commit ();
+    }
     throw;
   }
 }
@@ -1265,7 +1291,9 @@ MainService::cm_convert_to_pcell ()
 
   try {
 
-    manager ()->transaction (tl::to_string (tr ("Convert to PCell")));
+    if (manager ()) {
+      manager ()->transaction (tl::to_string (tr ("Convert to PCell")));
+    }
 
     std::vector<edt::Service::obj_iterator> to_delete;
     std::vector<lay::ObjectInstPath> new_selection;
@@ -1351,10 +1379,14 @@ MainService::cm_convert_to_pcell ()
 #endif
     }
 
-    manager ()->commit ();
+    if (manager ()) {
+      manager ()->commit ();
+    }
 
   } catch (...) {
-    manager ()->commit ();
+    if (manager ()) {
+      manager ()->commit ();
+    }
     throw;
   }
 }
@@ -1546,7 +1578,9 @@ MainService::cm_round_corners ()
   ep.merge (out, primary, 0 /*min_wc*/, true /*resolve holes*/, true /*min coherence*/);
 
   view ()->cancel_edits ();
-  manager ()->transaction (tl::to_string (tr ("Corner rounding operation on selection")));
+  if (manager ()) {
+    manager ()->transaction (tl::to_string (tr ("Corner rounding operation on selection")));
+  }
 
   //  Delete the current selection
   for (std::vector<edt::Service *>::const_iterator es = edt_services.begin (); es != edt_services.end (); ++es) {
@@ -1586,7 +1620,9 @@ MainService::cm_round_corners ()
     }
   }
 
-  manager ()->commit ();
+  if (manager ()) {
+    manager ()->commit ();
+  }
 }
 
 void
@@ -1672,7 +1708,9 @@ MainService::cm_size ()
   ep.size (primary, idx, idy, out, 2 /*mode, TODO: make variable*/, true /*resolve holes*/, true /*min coherence*/);
 
   view ()->cancel_edits ();
-  manager ()->transaction (tl::to_string (tr ("Sizing operation on selection")));
+  if (manager ()) {
+    manager ()->transaction (tl::to_string (tr ("Sizing operation on selection")));
+  }
 
   //  Delete the current selection
   for (std::vector<edt::Service *>::const_iterator es = edt_services.begin (); es != edt_services.end (); ++es) {
@@ -1712,7 +1750,9 @@ MainService::cm_size ()
     }
   }
 
-  manager ()->commit ();
+  if (manager ()) {
+    manager ()->commit ();
+  }
 }
 
 void
@@ -1792,7 +1832,9 @@ MainService::boolean_op (int mode)
   }
 
   view ()->cancel_edits ();
-  manager ()->transaction (tl::to_string (tr ("Boolean operation on selection")));
+  if (manager ()) {
+    manager ()->transaction (tl::to_string (tr ("Boolean operation on selection")));
+  }
 
   //  Delete the current selection
   //  NOTE: we delete only those shapes from the primary layer and keep shapes from other layers.
@@ -1835,7 +1877,9 @@ MainService::boolean_op (int mode)
     }
   }
 
-  manager ()->commit ();
+  if (manager ()) {
+    manager ()->commit ();
+  }
 }
 
 void 
@@ -1955,7 +1999,9 @@ MainService::cm_align ()
   if (! prim_box.empty ()) {
 
     view ()->cancel_edits ();
-    manager ()->transaction (tl::to_string (tr ("Alignment")));
+    if (manager ()) {
+      manager ()->transaction (tl::to_string (tr ("Alignment")));
+    }
 
     //  do the alignment
     for (std::vector<edt::Service *>::const_iterator es = edt_services.begin (); es != edt_services.end (); ++es) {
@@ -1996,7 +2042,9 @@ MainService::cm_align ()
 
     }
 
-    manager ()->commit ();
+    if (manager ()) {
+      manager ()->commit ();
+    }
 
   }
 }
@@ -2096,7 +2144,9 @@ MainService::cm_distribute ()
 
   {
     view ()->cancel_edits ();
-    manager ()->transaction (tl::to_string (tr ("Distribution")));
+    if (manager ()) {
+      manager ()->transaction (tl::to_string (tr ("Distribution")));
+    }
 
     //  do the distribution
     for (std::vector<edt::Service *>::const_iterator es = edt_services.begin (); es != edt_services.end (); ++es) {
@@ -2111,7 +2161,9 @@ MainService::cm_distribute ()
 
     }
 
-    manager ()->commit ();
+    if (manager ()) {
+      manager ()->commit ();
+    }
 
   }
 }
@@ -2151,10 +2203,12 @@ MainService::cm_make_array ()
   bool has_undo = (m_array_na * m_array_nb < 1000);
 
   //  No undo support currently - the undo buffering is pretty inefficient right now.
-  if (! has_undo) {
-    manager ()->clear ();
-  } else {
-    manager ()->transaction (tl::to_string (tr ("Make array")));
+  if (manager ()) {
+    if (! has_undo) {
+      manager ()->clear ();
+    } else {
+      manager ()->transaction (tl::to_string (tr ("Make array")));
+    }
   }
 
   tl::RelativeProgress progress (tl::to_string (tr ("Make array")), (size_t (m_array_na) * size_t (m_array_nb) - 1) * n, 1000);
@@ -2221,7 +2275,7 @@ MainService::cm_make_array ()
 
   }
 
-  if (has_undo) {
+  if (has_undo && manager ()) {
     manager ()->commit ();
   }
 }
@@ -2383,7 +2437,9 @@ MainService::cm_change_layer ()
 
     view ()->cancel_edits ();
 
-    manager ()->transaction (tl::to_string (tr ("Change layer")));
+    if (manager ()) {
+      manager ()->transaction (tl::to_string (tr ("Change layer")));
+    }
 
     db::Layout &layout = view ()->cellview (cv_index)->layout ();
 
@@ -2441,7 +2497,9 @@ MainService::cm_change_layer ()
     //  The selection is no longer valid
     view ()->clear_selection ();
 
-    manager ()->commit ();
+    if (manager ()) {
+      manager ()->commit ();
+    }
 
   } else {
     throw tl::Exception (tl::to_string (tr ("Nothing selected to switch layers for")));
diff --git a/src/edt/edt/edtPartialService.cc b/src/edt/edt/edtPartialService.cc
index 8950458f0..649be7f3f 100644
--- a/src/edt/edt/edtPartialService.cc
+++ b/src/edt/edt/edtPartialService.cc
@@ -1788,7 +1788,9 @@ PartialService::mouse_click_event (const db::DPoint &p, unsigned int buttons, bo
       //  stop dragging
       ui ()->ungrab_mouse (this);
       
-      manager ()->transaction (tl::to_string (tr ("Partial move")));
+      if (manager ()) {
+        manager ()->transaction (tl::to_string (tr ("Partial move")));
+      }
 
       //  heuristically, if there is just one edge selected: do not confine to the movement
       //  angle constraint - the edge usually is confined enough
@@ -1796,7 +1798,9 @@ PartialService::mouse_click_event (const db::DPoint &p, unsigned int buttons, bo
 
       transform_selection (move_trans);
 
-      manager ()->commit ();
+      if (manager ()) {
+        manager ()->commit ();
+      }
 
     }
 
@@ -1983,7 +1987,9 @@ PartialService::mouse_double_click_event (const db::DPoint &p, unsigned int butt
       partial_objects::iterator r = m_selection.begin (); // we assert above that we have at least one selected element
       if (! r->first.is_cell_inst ()) {
 
-        manager ()->transaction (tl::to_string (tr ("Insert point")));
+        if (manager ()) {
+          manager ()->transaction (tl::to_string (tr ("Insert point")));
+        }
 
         //  snap the point
         db::DPoint new_point_d = snap (p);
@@ -2050,7 +2056,9 @@ PartialService::mouse_double_click_event (const db::DPoint &p, unsigned int butt
 
           handle_guiding_shape_changes ();
 
-          manager ()->commit ();
+          if (manager ()) {
+            manager ()->commit ();
+          }
 
           selection_to_view ();
 
diff --git a/src/edt/edt/edtServiceImpl.cc b/src/edt/edt/edtServiceImpl.cc
index f11315018..a219d38bb 100644
--- a/src/edt/edt/edtServiceImpl.cc
+++ b/src/edt/edt/edtServiceImpl.cc
@@ -266,9 +266,13 @@ ShapeEditService::deliver_shape (const db::Polygon &poly)
 {
   if (m_combine_mode == CM_Add) {
 
-    manager ()->transaction (tl::to_string (tr ("Create polygon")));
+    if (manager ()) {
+      manager ()->transaction (tl::to_string (tr ("Create polygon")));
+    }
     cell ().shapes (layer ()).insert (poly);
-    manager ()->commit ();
+    if (manager ()) {
+      manager ()->commit ();
+    }
 
   } else {
 
@@ -326,7 +330,9 @@ ShapeEditService::deliver_shape (const db::Polygon &poly)
       result = input;
     }
 
-    manager ()->transaction (tl::to_string (tr ("Combine shape with background")));
+    if (manager ()) {
+      manager ()->transaction (tl::to_string (tr ("Combine shape with background")));
+    }
 
     //  Erase existing shapes
     for (std::vector<db::Shape>::const_iterator s = shapes.begin (); s != shapes.end (); ++s) {
@@ -341,7 +347,9 @@ ShapeEditService::deliver_shape (const db::Polygon &poly)
       cell ().shapes (layer ()).insert (*p);
     }
 
-    manager ()->commit ();
+    if (manager ()) {
+      manager ()->commit ();
+    }
 
   }
 }
@@ -350,9 +358,13 @@ void
 ShapeEditService::deliver_shape (const db::Path &path)
 {
   if (m_combine_mode == CM_Add) {
-    manager ()->transaction (tl::to_string (tr ("Create path")));
+    if (manager ()) {
+      manager ()->transaction (tl::to_string (tr ("Create path")));
+    }
     cell ().shapes (layer ()).insert (path);
-    manager ()->commit ();
+    if (manager ()) {
+      manager ()->commit ();
+    }
   } else {
     deliver_shape (path.polygon ());
   }
@@ -362,9 +374,13 @@ void
 ShapeEditService::deliver_shape (const db::Box &box)
 {
   if (m_combine_mode == CM_Add) {
-    manager ()->transaction (tl::to_string (tr ("Create box")));
+    if (manager ()) {
+      manager ()->transaction (tl::to_string (tr ("Create box")));
+    }
     cell ().shapes (layer ()).insert (box);
-    manager ()->commit ();
+    if (manager ()) {
+      manager ()->commit ();
+    }
   } else {
     deliver_shape (db::Polygon (box));
   }
@@ -912,9 +928,13 @@ TextService::do_finish_edit ()
 {
   get_edit_layer ();
 
-  manager ()->transaction (tl::to_string (tr ("Create text")));
+  if (manager ()) {
+    manager ()->transaction (tl::to_string (tr ("Create text")));
+  }
   cell ().shapes (layer ()).insert (get_text ());
-  manager ()->commit ();
+  if (manager ()) {
+    manager ()->commit ();
+  }
 
   commit_recent (view ());
 
@@ -1634,11 +1654,15 @@ InstService::do_finish_edit ()
         throw tl::Exception (tl::to_string (tr ("Inserting this instance would create a recursive hierarchy")));
       }
 
-      manager ()->transaction (tl::to_string (tr ("Create instance")), m_reference_transaction_id);
+      if (manager ()) {
+        manager ()->transaction (tl::to_string (tr ("Create instance")), m_reference_transaction_id);
+      }
       m_reference_transaction_id = 0;
       db::Instance i = cv->layout ().cell (cv.cell_index ()).insert (inst);
       cv->layout ().cleanup ();
-      manager ()->commit ();
+      if (manager ()) {
+        manager ()->commit ();
+      }
 
       commit_recent (view ());
 
diff --git a/src/img/img/imgService.cc b/src/img/img/imgService.cc
index 9724f902a..a21a80f7c 100644
--- a/src/img/img/imgService.cc
+++ b/src/img/img/imgService.cc
@@ -1481,9 +1481,13 @@ Service::menu_activated (const std::string &symbol)
 {
   if (symbol == "img::clear_all_images") {
 
-    manager ()->transaction (tl::to_string (tr ("Clear all images")));
+    if (manager ()) {
+      manager ()->transaction (tl::to_string (tr ("Clear all images")));
+    }
     clear_images ();
-    manager ()->commit ();
+    if (manager ()) {
+      manager ()->commit ();
+    }
 
   } else if (symbol == "img::add_image") {
 
@@ -1601,10 +1605,14 @@ Service::add_image ()
 
     clear_selection ();
 
-    manager ()->transaction (tl::to_string (tr ("Add image")));
+    if (manager ()) {
+      manager ()->transaction (tl::to_string (tr ("Add image")));
+    }
     new_image->set_z_position (top_z_position ());
     mp_view->annotation_shapes ().insert (db::DUserObject (new_image));
-    manager ()->commit ();
+    if (manager ()) {
+      manager ()->commit ();
+    }
 
   } else {
     delete new_image;
diff --git a/src/lay/lay/layFillDialog.cc b/src/lay/lay/layFillDialog.cc
index 8c7de86e7..119d60232 100644
--- a/src/lay/lay/layFillDialog.cc
+++ b/src/lay/lay/layFillDialog.cc
@@ -553,13 +553,19 @@ BEGIN_PROTECTED
 
   FillParameters fp = get_fill_parameters ();
 
-  mp_view->manager ()->transaction (tl::to_string (QObject::tr ("Fill")));
+  if (mp_view->manager ()) {
+    mp_view->manager ()->transaction (tl::to_string (QObject::tr ("Fill")));
+  }
 
   try {
     generate_fill (fp);
-    mp_view->manager ()->commit ();
+    if (mp_view->manager ()) {
+      mp_view->manager ()->commit ();
+    }
   } catch (...) {
-    mp_view->manager ()->cancel ();
+    if (mp_view->manager ()) {
+      mp_view->manager ()->cancel ();
+    }
     throw;
   }
 
diff --git a/src/lay/lay/laySearchReplaceDialog.cc b/src/lay/lay/laySearchReplaceDialog.cc
index 91f35fe62..dc856b88b 100644
--- a/src/lay/lay/laySearchReplaceDialog.cc
+++ b/src/lay/lay/laySearchReplaceDialog.cc
@@ -1814,10 +1814,14 @@ BEGIN_PROTECTED
 
   cancel_exec ();
 
-  mp_view->manager ()->transaction (tl::to_string (QObject::tr ("Delete all")));
+  if (mp_view->manager ()) {
+    mp_view->manager ()->transaction (tl::to_string (QObject::tr ("Delete all")));
+  }
   mp_view->cancel ();
   issue_query (build_delete_expression (), 0, false);
-  mp_view->manager ()->commit ();
+  if (mp_view->manager ()) {
+    mp_view->manager ()->commit ();
+  }
 
 END_PROTECTED
 }
@@ -1862,15 +1866,19 @@ BEGIN_PROTECTED
 
   if (! sel.empty ()) {
 
-    if (sender () == delete_selected_button) {
-      mp_view->manager ()->transaction (tl::to_string (QObject::tr ("Delete selected")));
-    } else {
-      mp_view->manager ()->transaction (tl::to_string (QObject::tr ("Replace selected")));
+    if (mp_view->manager ()) {
+      if (sender () == delete_selected_button) {
+        mp_view->manager ()->transaction (tl::to_string (QObject::tr ("Delete selected")));
+      } else {
+        mp_view->manager ()->transaction (tl::to_string (QObject::tr ("Replace selected")));
+      }
     }
 
     mp_view->cancel ();
     issue_query (m_execute_query, &selected_items, false);
-    mp_view->manager ()->commit ();
+    if (mp_view->manager ()) {
+      mp_view->manager ()->commit ();
+    }
 
     issue_query (m_find_query, 0, true);
 
@@ -1889,10 +1897,14 @@ BEGIN_PROTECTED
   m_execute_query.clear ();
   m_find_query.clear ();
 
-  mp_view->manager ()->transaction (tl::to_string (QObject::tr ("Replace all")));
+  if (mp_view->manager ()) {
+    mp_view->manager ()->transaction (tl::to_string (QObject::tr ("Replace all")));
+  }
   mp_view->cancel ();
   issue_query (build_replace_expression (), 0, false);
-  mp_view->manager ()->commit ();
+  if (mp_view->manager ()) {
+    mp_view->manager ()->commit ();
+  }
 
 END_PROTECTED
 }
@@ -1907,10 +1919,14 @@ BEGIN_PROTECTED
   m_execute_query.clear ();
   m_find_query.clear ();
 
-  mp_view->manager ()->transaction (tl::to_string (QObject::tr ("Execute custom query")));
+  if (mp_view->manager ()) {
+    mp_view->manager ()->transaction (tl::to_string (QObject::tr ("Execute custom query")));
+  }
   mp_view->cancel ();
   issue_query (tl::to_string (custom_query->toPlainText ()), 0, true);
-  mp_view->manager ()->commit ();
+  if (mp_view->manager ()) {
+    mp_view->manager ()->commit ();
+  }
 
 END_PROTECTED
 }
diff --git a/src/laybasic/laybasic/layLayoutViewBase.cc b/src/laybasic/laybasic/layLayoutViewBase.cc
index 533fb0213..fb4ffd020 100644
--- a/src/laybasic/laybasic/layLayoutViewBase.cc
+++ b/src/laybasic/laybasic/layLayoutViewBase.cc
@@ -3095,7 +3095,7 @@ LayoutViewBase::reload_layout (unsigned int cv_index)
   //  when reading the file, it must have the layers created as well
   lay::CellView cv_empty;
 
-  handle = new lay::LayoutHandle (new db::Layout (manager ()), filename);
+  handle = new lay::LayoutHandle (new db::Layout (is_editable (), manager ()), filename);
   handle->set_tech_name (technology);
   cv_empty.set (handle);
 
@@ -3108,7 +3108,7 @@ LayoutViewBase::reload_layout (unsigned int cv_index)
 
   //  create a new handle
   lay::CellView cv;
-  handle = new lay::LayoutHandle (new db::Layout (manager ()), filename);
+  handle = new lay::LayoutHandle (new db::Layout (is_editable (), manager ()), filename);
   cv.set (handle);
 
   try {
@@ -3337,7 +3337,7 @@ LayoutViewBase::create_layout (const std::string &technology, bool add_cellview,
 {
   const db::Technology *tech = db::Technologies::instance ()->technology_by_name (technology);
 
-  db::Layout *layout = new db::Layout (m_editable, manager ());
+  db::Layout *layout = new db::Layout (is_editable (), manager ());
   if (tech) {
     layout->dbu (tech->dbu ());
   }
@@ -3364,7 +3364,7 @@ LayoutViewBase::load_layout (const std::string &filename, const db::LoadLayoutOp
 
   //  create a new layout handle 
   lay::CellView cv;
-  lay::LayoutHandle *handle = new lay::LayoutHandle (new db::Layout (manager ()), filename);
+  lay::LayoutHandle *handle = new lay::LayoutHandle (new db::Layout (is_editable (), manager ()), filename);
   cv.set (handle);
 
   unsigned int cv_index;
diff --git a/src/layui/layui/layCellSelectionForm.cc b/src/layui/layui/layCellSelectionForm.cc
index 4fb40bb5f..75aa879eb 100644
--- a/src/layui/layui/layCellSelectionForm.cc
+++ b/src/layui/layui/layCellSelectionForm.cc
@@ -510,9 +510,13 @@ CellSelectionForm::show_cell ()
   QModelIndexList sel = mp_ui->lv_cells->selectionModel ()->selectedIndexes ();
   for (QModelIndexList::const_iterator s = sel.begin (); s != sel.end (); ++s) {
     db::cell_index_type ci = model->cell (*s)->cell_index ();
-    mp_view->manager ()->transaction (tl::to_string (QObject::tr ("Show cells")));
+    if (mp_view->manager ()) {
+      mp_view->manager ()->transaction (tl::to_string (QObject::tr ("Show cells")));
+    }
     mp_view->show_cell (ci, m_current_cv);
-    mp_view->manager ()->commit ();
+    if (mp_view->manager ()) {
+      mp_view->manager ()->commit ();
+    }
   }
 
   model->signal_data_changed ();
@@ -532,9 +536,13 @@ CellSelectionForm::hide_cell ()
   QModelIndexList sel = mp_ui->lv_cells->selectionModel ()->selectedIndexes ();
   for (QModelIndexList::const_iterator s = sel.begin (); s != sel.end (); ++s) {
     db::cell_index_type ci = model->cell (*s)->cell_index ();
-    mp_view->manager ()->transaction (tl::to_string (QObject::tr ("Hide cells")));
+    if (mp_view->manager ()) {
+      mp_view->manager ()->transaction (tl::to_string (QObject::tr ("Hide cells")));
+    }
     mp_view->hide_cell (ci, m_current_cv);
-    mp_view->manager ()->commit ();
+    if (mp_view->manager ()) {
+      mp_view->manager ()->commit ();
+    }
   }
 
   model->signal_data_changed ();
diff --git a/src/layui/layui/layEditLineStylesForm.cc b/src/layui/layui/layEditLineStylesForm.cc
index d600508ac..67fcf7dcf 100644
--- a/src/layui/layui/layEditLineStylesForm.cc
+++ b/src/layui/layui/layEditLineStylesForm.cc
@@ -203,9 +203,11 @@ EditLineStylesForm::sel_changed (QListWidgetItem *, QListWidgetItem *)
     return;
   }
 
-  manager ()->transaction (tl::to_string (QObject::tr ("Current style")));
-  manager ()->queue (this, new CurrentStyleOp (m_selected, mp_ui->style_items->currentRow ()));
-  manager ()->commit ();
+  if (manager ()) {
+    manager ()->transaction (tl::to_string (QObject::tr ("Current style")));
+    manager ()->queue (this, new CurrentStyleOp (m_selected, mp_ui->style_items->currentRow ()));
+    manager ()->commit ();
+  }
 
   update_current_item ();
 }
@@ -257,7 +259,9 @@ EditLineStylesForm::select_item (int index)
 void
 EditLineStylesForm::new_button_clicked ()
 {
-  manager ()->transaction (tl::to_string (QObject::tr ("New style")));
+  if (manager ()) {
+    manager ()->transaction (tl::to_string (QObject::tr ("New style")));
+  }
 
   lay::LineStyleInfo s;
   s.set_pattern (0x55555555, 32);
@@ -266,13 +270,17 @@ EditLineStylesForm::new_button_clicked ()
   update ();
   select_item (oi + std::distance (m_styles.begin (), m_styles.begin_custom ()));
 
-  manager ()->commit ();
+  if (manager ()) {
+    manager ()->commit ();
+  }
 }
 
 void 
 EditLineStylesForm::clone_button_clicked ()
 {
-  manager ()->transaction (tl::to_string (QObject::tr ("Clone style")));
+  if (manager ()) {
+    manager ()->transaction (tl::to_string (QObject::tr ("Clone style")));
+  }
 
   lay::LineStyles::iterator c = current ();
 
@@ -297,7 +305,9 @@ EditLineStylesForm::clone_button_clicked ()
   update ();
   select_item (oi + std::distance (m_styles.begin (), m_styles.begin_custom ()));
 
-  manager ()->commit ();
+  if (manager ()) {
+    manager ()->commit ();
+  }
 }
 
 void 
@@ -315,7 +325,9 @@ EditLineStylesForm::delete_button_clicked ()
       }
     }
 
-    manager ()->transaction (tl::to_string (QObject::tr ("Delete style")));
+    if (manager ()) {
+      manager ()->transaction (tl::to_string (QObject::tr ("Delete style")));
+    }
 
     if (mp_ui->style_items->currentRow () + 1 == mp_ui->style_items->count ()) {
       select_item (mp_ui->style_items->currentRow () - 1);
@@ -327,7 +339,9 @@ EditLineStylesForm::delete_button_clicked ()
     m_styles.renumber ();
     update ();
 
-    manager ()->commit ();
+    if (manager ()) {
+      manager ()->commit ();
+    }
 
   }
 
@@ -347,7 +361,9 @@ EditLineStylesForm::up_button_clicked ()
       for (lay::LineStyles::iterator i = m_styles.begin_custom (); i != m_styles.end (); ++i) {
         if (i->order_index () == oi - 1) {
 
-          manager ()->transaction (tl::to_string (QObject::tr ("Move style up")));
+          if (manager ()) {
+            manager ()->transaction (tl::to_string (QObject::tr ("Move style up")));
+          }
 
           lay::LineStyleInfo info;
           info = *i;
@@ -361,7 +377,9 @@ EditLineStylesForm::up_button_clicked ()
           update ();
           select_item (oi - 2 + std::distance (m_styles.begin (), m_styles.begin_custom ()));
 
-          manager ()->commit ();
+          if (manager ()) {
+            manager ()->commit ();
+          }
 
           return;
 
@@ -385,7 +403,9 @@ EditLineStylesForm::down_button_clicked ()
     for (lay::LineStyles::iterator i = m_styles.begin_custom (); i != m_styles.end (); ++i) {
       if (i->order_index () == oi + 1) {
 
-        manager ()->transaction (tl::to_string (QObject::tr ("Move style down")));
+        if (manager ()) {
+          manager ()->transaction (tl::to_string (QObject::tr ("Move style down")));
+        }
 
         lay::LineStyleInfo info;
         info = *i;
@@ -399,7 +419,9 @@ EditLineStylesForm::down_button_clicked ()
         update ();
         select_item (oi + std::distance (m_styles.begin (), m_styles.begin_custom ()));
 
-        manager ()->commit ();
+        if (manager ()) {
+          manager ()->commit ();
+        }
 
         return;
 
@@ -420,49 +442,73 @@ EditLineStylesForm::editor_size_changed ()
 void
 EditLineStylesForm::size_changed ()
 {
-  manager ()->transaction (tl::to_string (QObject::tr ("Change style size")));
+  if (manager ()) {
+    manager ()->transaction (tl::to_string (QObject::tr ("Change style size")));
+  }
   mp_ui->editor->set_size (mp_ui->w_spin_box->value ());
-  manager ()->commit ();
+  if (manager ()) {
+    manager ()->commit ();
+  }
 }
 
 void 
 EditLineStylesForm::invert_button_clicked ()
 {
-  manager ()->transaction (tl::to_string (QObject::tr ("Invert style")));
+  if (manager ()) {
+    manager ()->transaction (tl::to_string (QObject::tr ("Invert style")));
+  }
   mp_ui->editor->invert ();
-  manager ()->commit ();
+  if (manager ()) {
+    manager ()->commit ();
+  }
 }
 
 void 
 EditLineStylesForm::clear_button_clicked ()
 {
-  manager ()->transaction (tl::to_string (QObject::tr ("Clear style")));
+  if (manager ()) {
+    manager ()->transaction (tl::to_string (QObject::tr ("Clear style")));
+  }
   mp_ui->editor->clear ();
-  manager ()->commit ();
+  if (manager ()) {
+    manager ()->commit ();
+  }
 }
 
 void 
 EditLineStylesForm::fliph_button_clicked ()
 {
-  manager ()->transaction (tl::to_string (QObject::tr ("Flip style")));
+  if (manager ()) {
+    manager ()->transaction (tl::to_string (QObject::tr ("Flip style")));
+  }
   mp_ui->editor->fliph ();
-  manager ()->commit ();
+  if (manager ()) {
+    manager ()->commit ();
+  }
 }
 
 void 
 EditLineStylesForm::sleft_button_clicked ()
 {
-  manager ()->transaction (tl::to_string (QObject::tr ("Shift left")));
+  if (manager ()) {
+    manager ()->transaction (tl::to_string (QObject::tr ("Shift left")));
+  }
   mp_ui->editor->shift (-1);
-  manager ()->commit ();
+  if (manager ()) {
+    manager ()->commit ();
+  }
 }
 
 void 
 EditLineStylesForm::sright_button_clicked ()
 {
-  manager ()->transaction (tl::to_string (QObject::tr ("Shift right")));
+  if (manager ()) {
+    manager ()->transaction (tl::to_string (QObject::tr ("Shift right")));
+  }
   mp_ui->editor->shift (1);
-  manager ()->commit ();
+  if (manager ()) {
+    manager ()->commit ();
+  }
 }
 
 void 
diff --git a/src/layui/layui/layEditStipplesForm.cc b/src/layui/layui/layEditStipplesForm.cc
index f51826dc1..21feb17cc 100644
--- a/src/layui/layui/layEditStipplesForm.cc
+++ b/src/layui/layui/layEditStipplesForm.cc
@@ -231,9 +231,11 @@ EditStipplesForm::sel_changed (QListWidgetItem *, QListWidgetItem *)
     return;
   }
 
-  manager ()->transaction (tl::to_string (QObject::tr ("Current pattern")));
-  manager ()->queue (this, new CurrentPatternOp (m_selected, mp_ui->stipple_items->currentRow ()));
-  manager ()->commit ();
+  if (manager ()) {
+    manager ()->transaction (tl::to_string (QObject::tr ("Current pattern")));
+    manager ()->queue (this, new CurrentPatternOp (m_selected, mp_ui->stipple_items->currentRow ()));
+    manager ()->commit ();
+  }
 
   update_current_item ();
 }
@@ -280,7 +282,9 @@ EditStipplesForm::select_item (int index)
   mp_ui->stipple_items->setCurrentItem (mp_ui->stipple_items->item (index));
   mp_ui->stipple_items->scrollToItem (mp_ui->stipple_items->currentItem ());
 
-  manager ()->queue (this, new CurrentPatternOp (m_selected, index));
+  if (manager ()) {
+    manager ()->queue (this, new CurrentPatternOp (m_selected, index));
+  }
 
   update_current_item ();
 
@@ -290,7 +294,9 @@ EditStipplesForm::select_item (int index)
 void
 EditStipplesForm::new_button_clicked ()
 {
-  manager ()->transaction (tl::to_string (QObject::tr ("New pattern")));
+  if (manager ()) {
+    manager ()->transaction (tl::to_string (QObject::tr ("New pattern")));
+  }
 
   lay::DitherPatternInfo p;
   unsigned int oi = m_pattern.begin ()[m_pattern.add_pattern (p)].order_index () - 1;
@@ -298,13 +304,17 @@ EditStipplesForm::new_button_clicked ()
   update ();
   select_item (oi + std::distance (m_pattern.begin (), m_pattern.begin_custom ()));
 
-  manager ()->commit ();
+  if (manager ()) {
+    manager ()->commit ();
+  }
 }
 
 void 
 EditStipplesForm::clone_button_clicked ()
 {
-  manager ()->transaction (tl::to_string (QObject::tr ("Clone pattern")));
+  if (manager ()) {
+    manager ()->transaction (tl::to_string (QObject::tr ("Clone pattern")));
+  }
 
   lay::DitherPattern::iterator c = current ();
 
@@ -329,7 +339,9 @@ EditStipplesForm::clone_button_clicked ()
   update ();
   select_item (oi + std::distance (m_pattern.begin (), m_pattern.begin_custom ()));
 
-  manager ()->commit ();
+  if (manager ()) {
+    manager ()->commit ();
+  }
 }
 
 void 
@@ -347,7 +359,9 @@ EditStipplesForm::delete_button_clicked ()
       }
     }
 
-    manager ()->transaction (tl::to_string (QObject::tr ("Delete pattern")));
+    if (manager ()) {
+      manager ()->transaction (tl::to_string (QObject::tr ("Delete pattern")));
+    }
 
     if (mp_ui->stipple_items->currentRow () + 1 == mp_ui->stipple_items->count ()) {
       select_item (mp_ui->stipple_items->currentRow () - 1);
@@ -359,7 +373,9 @@ EditStipplesForm::delete_button_clicked ()
     m_pattern.renumber ();
     update ();
 
-    manager ()->commit ();
+    if (manager ()) {
+      manager ()->commit ();
+    }
 
   }
 
@@ -379,7 +395,9 @@ EditStipplesForm::up_button_clicked ()
       for (lay::DitherPattern::iterator i = m_pattern.begin_custom (); i != m_pattern.end (); ++i) {
         if (i->order_index () == oi - 1) {
 
-          manager ()->transaction (tl::to_string (QObject::tr ("Move pattern up")));
+          if (manager ()) {
+            manager ()->transaction (tl::to_string (QObject::tr ("Move pattern up")));
+          }
 
           lay::DitherPatternInfo info;
           info = *i;
@@ -393,7 +411,9 @@ EditStipplesForm::up_button_clicked ()
           update ();
           select_item (oi - 2 + std::distance (m_pattern.begin (), m_pattern.begin_custom ()));
 
-          manager ()->commit ();
+          if (manager ()) {
+            manager ()->commit ();
+          }
 
           return;
 
@@ -417,7 +437,9 @@ EditStipplesForm::down_button_clicked ()
     for (lay::DitherPattern::iterator i = m_pattern.begin_custom (); i != m_pattern.end (); ++i) {
       if (i->order_index () == oi + 1) {
 
-        manager ()->transaction (tl::to_string (QObject::tr ("Move pattern down")));
+        if (manager ()) {
+          manager ()->transaction (tl::to_string (QObject::tr ("Move pattern down")));
+        }
 
         lay::DitherPatternInfo info;
         info = *i;
@@ -431,7 +453,9 @@ EditStipplesForm::down_button_clicked ()
         update ();
         select_item (oi + std::distance (m_pattern.begin (), m_pattern.begin_custom ()));
 
-        manager ()->commit ();
+        if (manager ()) {
+          manager ()->commit ();
+        }
 
         return;
 
@@ -455,81 +479,121 @@ EditStipplesForm::editor_size_changed ()
 void
 EditStipplesForm::size_changed ()
 {
-  manager ()->transaction (tl::to_string (QObject::tr ("Change pattern size")));
+  if (manager ()) {
+    manager ()->transaction (tl::to_string (QObject::tr ("Change pattern size")));
+  }
   mp_ui->editor->set_size (mp_ui->w_spin_box->value (), mp_ui->h_spin_box->value ());
-  manager ()->commit ();
+  if (manager ()) {
+    manager ()->commit ();
+  }
 }
 
 void 
 EditStipplesForm::invert_button_clicked ()
 {
-  manager ()->transaction (tl::to_string (QObject::tr ("Invert pattern")));
+  if (manager ()) {
+    manager ()->transaction (tl::to_string (QObject::tr ("Invert pattern")));
+  }
   mp_ui->editor->invert ();
-  manager ()->commit ();
+  if (manager ()) {
+    manager ()->commit ();
+  }
 }
 
 void 
 EditStipplesForm::clear_button_clicked ()
 {
-  manager ()->transaction (tl::to_string (QObject::tr ("Clear pattern")));
+  if (manager ()) {
+    manager ()->transaction (tl::to_string (QObject::tr ("Clear pattern")));
+  }
   mp_ui->editor->clear ();
-  manager ()->commit ();
+  if (manager ()) {
+    manager ()->commit ();
+  }
 }
 
 void 
 EditStipplesForm::rotate_button_clicked ()
 {
-  manager ()->transaction (tl::to_string (QObject::tr ("Rotate pattern")));
+  if (manager ()) {
+    manager ()->transaction (tl::to_string (QObject::tr ("Rotate pattern")));
+  }
   mp_ui->editor->rotate (90);
-  manager ()->commit ();
+  if (manager ()) {
+    manager ()->commit ();
+  }
 }
 
 void 
 EditStipplesForm::fliph_button_clicked ()
 {
-  manager ()->transaction (tl::to_string (QObject::tr ("Flip horizontal")));
+  if (manager ()) {
+    manager ()->transaction (tl::to_string (QObject::tr ("Flip horizontal")));
+  }
   mp_ui->editor->fliph ();
-  manager ()->commit ();
+  if (manager ()) {
+    manager ()->commit ();
+  }
 }
 
 void 
 EditStipplesForm::flipv_button_clicked ()
 {
-  manager ()->transaction (tl::to_string (QObject::tr ("Flip vertical")));
+  if (manager ()) {
+    manager ()->transaction (tl::to_string (QObject::tr ("Flip vertical")));
+  }
   mp_ui->editor->flipv ();
-  manager ()->commit ();
+  if (manager ()) {
+    manager ()->commit ();
+  }
 }
 
 void 
 EditStipplesForm::sleft_button_clicked ()
 {
-  manager ()->transaction (tl::to_string (QObject::tr ("Shift left")));
+  if (manager ()) {
+    manager ()->transaction (tl::to_string (QObject::tr ("Shift left")));
+  }
   mp_ui->editor->shift (-1, 0);
-  manager ()->commit ();
+  if (manager ()) {
+    manager ()->commit ();
+  }
 }
 
 void 
 EditStipplesForm::sup_button_clicked ()
 {
-  manager ()->transaction (tl::to_string (QObject::tr ("Shift up")));
+  if (manager ()) {
+    manager ()->transaction (tl::to_string (QObject::tr ("Shift up")));
+  }
   mp_ui->editor->shift (0, 1);
-  manager ()->commit ();
+  if (manager ()) {
+    manager ()->commit ();
+  }
 }
 
 void 
 EditStipplesForm::sright_button_clicked ()
 {
-  manager ()->transaction (tl::to_string (QObject::tr ("Shift right")));
+  if (manager ()) {
+    manager ()->transaction (tl::to_string (QObject::tr ("Shift right")));
+  }
   mp_ui->editor->shift (1, 0);
-  manager ()->commit ();
+  if (manager ()) {
+    manager ()->commit ();
+  }
 }
 
 void 
 EditStipplesForm::sdown_button_clicked ()
 {
-  manager ()->transaction (tl::to_string (QObject::tr ("Shift down")));
+  if (manager ()) {
+    manager ()->transaction (tl::to_string (QObject::tr ("Shift down")));
+  }
   mp_ui->editor->shift (0, -1);
-  manager ()->commit ();
+  if (manager ()) {
+    manager ()->commit ();
+  }
 }
 
 void 
diff --git a/src/layui/layui/layLayoutPropertiesForm.cc b/src/layui/layui/layLayoutPropertiesForm.cc
index 55b5322d2..f247aea22 100644
--- a/src/layui/layui/layLayoutPropertiesForm.cc
+++ b/src/layui/layui/layLayoutPropertiesForm.cc
@@ -103,9 +103,13 @@ LayoutPropertiesForm::commit ()
   }
 
   if (fabs (dbu - layout.dbu ()) > 1e-6) {
-    mp_view->manager ()->transaction (tl::to_string (QObject::tr ("Change layout's database unit"))); 
+    if (mp_view->manager ()) {
+      mp_view->manager ()->transaction (tl::to_string (QObject::tr ("Change layout's database unit")));
+    }
     layout.dbu (dbu);
-    mp_view->manager ()->commit ();
+    if (mp_view->manager ()) {
+      mp_view->manager ()->commit ();
+    }
   }
 
   //  get the selected technology name
@@ -156,9 +160,13 @@ LayoutPropertiesForm::prop_pb_clicked ()
   lay::UserPropertiesForm props_form (this);
   if (props_form.show (mp_view, m_index, prop_id, layout.begin_meta (), layout.end_meta ())) {
 
-    mp_view->manager ()->transaction (tl::to_string (QObject::tr ("Edit layout's user properties"))); 
+    if (mp_view->manager ()) {
+      mp_view->manager ()->transaction (tl::to_string (QObject::tr ("Edit layout's user properties")));
+    }
     layout.prop_id (prop_id);
-    mp_view->manager ()->commit ();
+    if (mp_view->manager ()) {
+      mp_view->manager ()->commit ();
+    }
 
   }
 }
diff --git a/src/layui/layui/layWidgets.cc b/src/layui/layui/layWidgets.cc
index 93367db93..fafdf6b53 100644
--- a/src/layui/layui/layWidgets.cc
+++ b/src/layui/layui/layWidgets.cc
@@ -403,7 +403,9 @@ BEGIN_PROTECTED
         }
       }
 
-      mp_private->view->manager ()->transaction (tl::to_string (QObject::tr ("New layer"))); 
+      if (mp_private->view->manager ()) {
+        mp_private->view->manager ()->transaction (tl::to_string (QObject::tr ("New layer")));
+      }
 
       unsigned int l = cv->layout ().insert_layer (lp);
       std::vector <unsigned int> nl;
@@ -411,7 +413,9 @@ BEGIN_PROTECTED
       mp_private->view->add_new_layers (nl, mp_private->cv_index);
       mp_private->view->update_content ();
 
-      mp_private->view->manager ()->commit ();
+      if (mp_private->view->manager ()) {
+        mp_private->view->manager ()->commit ();
+      }
 
       //  NOTE: add_new_layers has triggered update_layer_list which already added the new layer
       set_current_layer (lp);