diff --git a/htmlgen/htmlgen.py b/htmlgen/htmlgen.py
index 104040ce..b9e5e8c9 100755
--- a/htmlgen/htmlgen.py
+++ b/htmlgen/htmlgen.py
@@ -38,6 +38,9 @@ else:
 
 db_dir = os.path.join(get_setting("XRAY_DATABASE_DIR"), get_setting("XRAY_DATABASE"))
 def db_open(fn):
+    filename = os.path.join(db_dir, fn)
+    if not os.path.exists(filename):
+        return open("/dev/null")
     return open(os.path.join(db_dir, fn))
 
 def out_open(fn):
@@ -233,6 +236,7 @@ with out_open("index.html") as f:
         for grid_x in range(grid_range[0], grid_range[2]+1):
             tilename = grid_map[(grid_x, grid_y)]
             tiledata = grid["tiles"][tilename]
+            segdata = None
 
             bgcolor = "#aaaaaa"
             if tiledata["type"] in ["INT_L", "INT_R"]: bgcolor="#aaaaff"
@@ -253,7 +257,10 @@ with out_open("index.html") as f:
                     title.append("%s site: %s" % (sitetype, sitename))
 
             if "segment" in tiledata:
-                title.append("Baseaddr: %s %d" % tuple(segdata["baseaddr"]))
+                if "baseaddr" in segdata:
+                    title.append("Baseaddr: %s %d" % tuple(segdata["baseaddr"]))
+                else:
+                    print("Warning: no baseaddr in segment %s (via tile %s)." % (tiledata["segment"], tilename))
 
             print("<td bgcolor=\"%s\" align=\"center\" title=\"%s\"><span style=\"font-size:10px\">" % (bgcolor, "\n".join(title)), file=f)
             if "segment" in tiledata: