diff --git a/src/frontend/diff.c b/src/frontend/diff.c
index e11e6ece0..4412bb7da 100644
--- a/src/frontend/diff.c
+++ b/src/frontend/diff.c
@@ -44,6 +44,7 @@ canonical_name(const char *name, DSTRINGPTR dbuf_p,
         f_ok &= ds_cat_mem(dbuf_p, sz_branch,
                 sizeof sz_branch / sizeof *sz_branch - 1) == DS_E_OK;
         if (!f_ok) {
+            fprintf(stderr, "Error: DS could not convert %s\n", name);
             controlled_exit(-1);
         }
         return ds_get_buf(dbuf_p);
@@ -56,6 +57,7 @@ canonical_name(const char *name, DSTRINGPTR dbuf_p,
         f_ok &= ds_cat_str(dbuf_p, name) == DS_E_OK;
         f_ok &= ds_cat_char(dbuf_p, ')') == DS_E_OK;
         if (!f_ok) {
+            fprintf(stderr, "Error: DS could not convert %s\n", name);
             controlled_exit(-1);
         }
         return ds_get_buf(dbuf_p);
@@ -68,6 +70,7 @@ canonical_name(const char *name, DSTRINGPTR dbuf_p,
      * changing the original, but in the current use cases that is
      * not an issue. */
     if (ds_cat_str(dbuf_p, name) != DS_E_OK) {
+        fprintf(stderr, "Error: DS could not convert %s\n", name);
         controlled_exit(-1);
     }
     return ds_get_buf(dbuf_p);
diff --git a/src/frontend/inp.c b/src/frontend/inp.c
index e6660442e..fc9b5b5a3 100644
--- a/src/frontend/inp.c
+++ b/src/frontend/inp.c
@@ -1307,6 +1307,12 @@ inp_dodeck(
                     if (strstr(dd->line, ".model"))
                         fprintf(stderr, "Warning: Model issue on line %d :\n  %.*s ...\n%s\n",
                                    dd->linenum_orig, 72, dd->line, dd->error);
+                    else if (dd->linenum_orig == 0) {
+                        fprintf(stderr, "Error on line:\n  %s\n%s\n",
+                                   dd->line, dd->error);
+                        have_err = TRUE;
+                        return 1;
+                    }
                     else {
                         fprintf(stderr, "Error on line %d or its substitute:\n  %s\n%s\n",
                                    dd->linenum_orig, dd->line, dd->error);
diff --git a/src/frontend/inpcom.c b/src/frontend/inpcom.c
index c4851a8b1..7b6ad0f89 100644
--- a/src/frontend/inpcom.c
+++ b/src/frontend/inpcom.c
@@ -1273,6 +1273,7 @@ struct inp_read_t inp_read( FILE *fp, int call_depth, const char *dir_name,
                     strcat(buffer, "\n");
                 }
                 else { /* No good way to report this so just die */
+                    fprintf(stderr, "Error: IPC status not o.k.\n");
                     controlled_exit(EXIT_FAILURE);
                 }
             }
@@ -1758,7 +1759,7 @@ static char *inp_pathresolve(const char *name)
             name[2] == DIR_TERM_LINUX) {
         DS_CREATE(ds, 100);
         if (ds_cat_str(&ds, name) != 0) {
-            fprintf(stderr, "Unable to copy string while resolving path");
+            fprintf(stderr, "Error: Unable to copy string while resolving path");
             controlled_exit(EXIT_FAILURE);
         }
         char *const buf = ds_get_buf(&ds);
@@ -1821,7 +1822,7 @@ static char *inp_pathresolve(const char *name)
 
             if (rc_ds != 0) { /* unable to build string */
                 (void) fprintf(cp_err,
-                        "Unable to build path name in inp_pathresolve");
+                        "Error: Unable to build path name in inp_pathresolve");
                 controlled_exit(EXIT_FAILURE);
             }
 
@@ -1873,7 +1874,7 @@ static char *inp_pathresolve_at(const char *name, const char *dir)
         DS_CREATE(ds, 100);
         if (ds_cat_printf(&ds, ".%c%s", DIR_TERM, name) != 0) {
             (void) fprintf(cp_err,
-                    "Unable to build \".\" path name in inp_pathresolve_at");
+                    "Error: Unable to build \".\" path name in inp_pathresolve_at");
             controlled_exit(EXIT_FAILURE);
         }
         char * const r = inp_pathresolve(ds_get_buf(&ds));
@@ -1901,7 +1902,7 @@ static char *inp_pathresolve_at(const char *name, const char *dir)
         rc_ds |= ds_cat_str(&ds, name); /* append the file name */
 
         if (rc_ds != 0) {
-            (void) fprintf(cp_err, "Unable to build \"dir\" path name "
+            (void) fprintf(cp_err, "Error: Unable to build \"dir\" path name "
                     "in inp_pathresolve_at");
             controlled_exit(EXIT_FAILURE);
         }
@@ -3051,7 +3052,7 @@ static void inp_change_quotes(char *s)
 static void add_name(struct names *p, char *name)
 {
     if (p->num_names >= N_SUBCKT_W_PARAMS) {
-        fprintf(stderr, "ERROR, N_SUBCKT_W_PARMS overflow\n");
+        fprintf(stderr, "ERROR: N_SUBCKT_W_PARMS overflow, more than %d subcircuits\n", N_SUBCKT_W_PARAMS);
         controlled_exit(EXIT_FAILURE);
     }
 
@@ -3748,7 +3749,7 @@ static void free_function(struct function *fcn)
 static void new_function_parameter(struct function *fcn, char *parameter)
 {
     if (fcn->num_parameters >= N_PARAMS) {
-        fprintf(stderr, "ERROR, N_PARAMS overflow\n");
+        fprintf(stderr, "ERROR, N_PARAMS overflow, more than %d parameters\n", N_PARAMS);
         controlled_exit(EXIT_FAILURE);
     }
 
@@ -4926,6 +4927,7 @@ static struct card *inp_reorder_params_subckt(
     }
 
     /* the terminating `.ends' deck wasn't found */
+    fprintf(stderr, "Error: Missing .ends statement\n");
     controlled_exit(EXIT_FAILURE);
 }
 
@@ -10091,7 +10093,7 @@ struct nscope *inp_add_levels(struct card *deck)
             }
             else if (ciprefix(".ends", curr_line)) {
                 if (lvl == root) {
-                    fprintf(stderr, ".subckt/.ends not balanced\n");
+                    fprintf(stderr, "Error: .subckt/.ends not balanced\n");
                     controlled_exit(1);
                 }
                 card->level = lvl;
diff --git a/src/frontend/numparam/mystring.c b/src/frontend/numparam/mystring.c
index 7793473b1..fe58576e1 100644
--- a/src/frontend/numparam/mystring.c
+++ b/src/frontend/numparam/mystring.c
@@ -74,6 +74,7 @@ void
 sadd(DSTRINGPTR dstr_p, const char *t)
 {
     if (ds_cat_str(dstr_p, t) != DS_E_OK) {
+        fprintf(stderr, "Error: DS could not add string %s\n", t);
         controlled_exit(-1);
     }
 }
@@ -86,6 +87,7 @@ void
 cadd(DSTRINGPTR dstr_p, char c)
 {
     if (ds_cat_char(dstr_p, c) != DS_E_OK) {
+        fprintf(stderr, "Error: DS could not add character %c\n", c);
         controlled_exit(-1);
     }
 }
@@ -100,6 +102,7 @@ scopyd(DSTRINGPTR dst, const DSTRINGPTR src)  /* returns success flag */
 {
     ds_clear(dst);
     if (ds_cat_ds(dst, src) != DS_E_OK) {
+        fprintf(stderr, "Error: DS could not copy string\n");
         controlled_exit(-1);
     }
 }
@@ -114,6 +117,7 @@ scopys(DSTRINGPTR s, const char *t)     /* returns success flag */
 {
     ds_clear(s);
     if (ds_cat_str(s, t) != DS_E_OK) {
+        fprintf(stderr, "Error: DS could not copy string %s\n", t);
         controlled_exit(-1);
     }
 }
@@ -129,6 +133,7 @@ pscopy(DSTRINGPTR dstr_p, const char *t, const char *stop)
 
     ds_clear(dstr_p);
     if (ds_cat_mem(dstr_p, t, (size_t) (stop - t)) != DS_E_OK) {
+        fprintf(stderr, "Error: DS could not copy partially string %s\n", t);
         controlled_exit(-1);
     }
 
diff --git a/src/frontend/numparam/xpressn.c b/src/frontend/numparam/xpressn.c
index f4732ef74..1f523f66c 100644
--- a/src/frontend/numparam/xpressn.c
+++ b/src/frontend/numparam/xpressn.c
@@ -336,6 +336,7 @@ dicostack_pop(dico_t *dico)
             ds_clear(&param_name);
             if (ds_cat_printf(&param_name, "%s.%s",
                     inst_name, entry->symbol) != DS_E_OK) {
+                fprintf(stderr, "Error: DS could not add string %s\n", inst_name);
                 controlled_exit(-1);
             }
             nupa_add_inst_param(ds_get_buf(&param_name), entry->vl);
diff --git a/src/frontend/runcoms.c b/src/frontend/runcoms.c
index e23623373..9d52e192e 100644
--- a/src/frontend/runcoms.c
+++ b/src/frontend/runcoms.c
@@ -34,6 +34,7 @@ Modified: 2000 AlansFixes
 static int dosim(char *what, wordlist *wl);
 extern struct INPmodel *modtab;
 extern struct dbcomm *dbs;
+extern void NIresetwarnmsg(void);
 
 /* Routines for the commands op, tran, ac, dc, listing, device, state,
  * resume, stop, trace, run, end.  Op, tran, ac, and dc cause the action
@@ -261,6 +262,8 @@ static int dosim(
         return 0;
     }
 
+    NIresetwarnmsg();
+
     /* From now on until the next prompt, an interrupt will just
      * set a flag and let spice finish up, then control will be
      * passed back to the user.
diff --git a/src/frontend/vectors.c b/src/frontend/vectors.c
index 31933b892..bbd3801c2 100644
--- a/src/frontend/vectors.c
+++ b/src/frontend/vectors.c
@@ -69,6 +69,7 @@ static void vec_rebuild_lookup_table(struct plot *pl)
         for (d = pl->pl_dvecs; d; d = d->v_next) {
             ds_clear(&dbuf);
             if (ds_cat_str_case(&dbuf, d->v_name, ds_case_lower) != DS_E_OK) {
+                fprintf(stderr, "Error: DS could not add string %s\n", d->v_name);
                 controlled_exit(-1);
             }
             char * const lower_name = ds_get_buf(&dbuf);
@@ -181,6 +182,7 @@ static struct dvec *findvec(char *word, struct plot *pl)
 
     DS_CREATE(dbuf, 200); /* make dynamic buffer */
     if (ds_cat_str_case(&dbuf, word, ds_case_lower) != DS_E_OK) {
+        fprintf(stderr, "Error: DS could not add string %s\n", word);
         controlled_exit(-1);
     }
     char * const lower_name = ds_get_buf(&dbuf);
@@ -197,6 +199,7 @@ static struct dvec *findvec(char *word, struct plot *pl)
                 ds_case_lower) == DS_E_OK;
         f_ok &= ds_cat_char(&dbuf, ')') == DS_E_OK;
         if (!f_ok) {
+            fprintf(stderr, "Error: DS could not add string V() around %s\n", word);
             controlled_exit(-1);
         }
         char * const node_name = ds_get_buf(&dbuf);
diff --git a/src/include/ngspice/cktdefs.h b/src/include/ngspice/cktdefs.h
index b849c2b6f..b9b14a9cc 100644
--- a/src/include/ngspice/cktdefs.h
+++ b/src/include/ngspice/cktdefs.h
@@ -480,6 +480,7 @@ extern void NIdestroy(CKTcircuit *);
 extern int NIinit(CKTcircuit  *);
 extern int NIintegrate(CKTcircuit *, double *, double *, double , int);
 extern int NIiter(CKTcircuit * , int);
+extern void NIresetwarnmsg(void);
 extern int NIpzMuller(PZtrial **, PZtrial *);
 extern int NIpzComplex(PZtrial **, PZtrial *);
 extern int NIpzSym(PZtrial **, PZtrial *);
diff --git a/src/maths/ni/niiter.c b/src/maths/ni/niiter.c
index 94e64e25f..fd7966dc9 100644
--- a/src/maths/ni/niiter.c
+++ b/src/maths/ni/niiter.c
@@ -20,6 +20,9 @@ Modified: 2001 AlansFixes
 #include "ngspice/sperror.h"
 #include "ngspice/fteext.h"
 
+/* Limit the number of 'singular matrix' warnings */
+static int msgcount = 0;
+void NIresetwarnmsg(void);
 
 /* NIiter() - return value is non-zero for convergence failure */
 
@@ -32,8 +35,6 @@ NIiter(CKTcircuit *ckt, int maxIter)
     int iterno = 0;
     int ipass = 0;
 
-    static int msgcount = 0;
-
     /* some convergence issues that get resolved by increasing max iter */
     if (maxIter < 100)
         maxIter = 100;
@@ -123,7 +124,10 @@ NIiter(CKTcircuit *ckt, int maxIter)
                      */
                     if (ft_ngdebug || msgcount < 6) {
                         SMPgetError(ckt->CKTmatrix, &i, &j);
-                        SPfrontEnd->IFerrorf(ERR_WARNING, "singular matrix:  check nodes %s and %s\n", NODENAME(ckt, i), NODENAME(ckt, j));
+                        if(eq(NODENAME(ckt, i), NODENAME(ckt, j)))
+                            SPfrontEnd->IFerrorf(ERR_WARNING, "singular matrix:  check node %s\n", NODENAME(ckt, i));
+                        else
+                            SPfrontEnd->IFerrorf(ERR_WARNING, "singular matrix:  check nodes %s and %s\n", NODENAME(ckt, i), NODENAME(ckt, j));
                         msgcount += 1;
                     }
                     ckt->CKTstat->STATnumIter += iterno;
@@ -280,3 +284,7 @@ NIiter(CKTcircuit *ckt, int maxIter)
     }
     /*NOTREACHED*/
 }
+
+void NIresetwarnmsg(void) {
+    msgcount = 0;
+};
diff --git a/src/misc/string.c b/src/misc/string.c
index 5a06b9599..147fe3648 100644
--- a/src/misc/string.c
+++ b/src/misc/string.c
@@ -110,6 +110,7 @@ char *tvprintf(const char *fmt, va_list args)
          * memory was exhausted) with the old behavior */
 
         if (nchars < 0) {
+            fprintf(stderr, "Error: tvprintf failed\n");
             controlled_exit(-1);
         }
 
diff --git a/src/spicelib/analysis/acan.c b/src/spicelib/analysis/acan.c
index da8d5bd39..1c45856c9 100644
--- a/src/spicelib/analysis/acan.c
+++ b/src/spicelib/analysis/acan.c
@@ -86,8 +86,9 @@ ACan(CKTcircuit *ckt, int restart)
                 fprintf(stderr, "ERROR: AC startfreq <= 0\n");
                 return E_PARMVAL;
             }
-            job->ACfreqDelta =
-                exp(log(10.0)/job->ACnumberSteps);
+            double num_steps = floor(fabs(log10(job->ACstopFreq/job->ACstartFreq))*job->ACnumberSteps);
+            job->ACfreqDelta = exp((log(job->ACstopFreq/job->ACstartFreq))/ num_steps);
+
             break;
         case OCTAVE:
             if (job->ACstartFreq <= 0) {
diff --git a/src/spicelib/devices/txl/txlload.c b/src/spicelib/devices/txl/txlload.c
index 212fad344..2206550f5 100644
--- a/src/spicelib/devices/txl/txlload.c
+++ b/src/spicelib/devices/txl/txlload.c
@@ -296,6 +296,7 @@ copy_tx(TXLine *new, TXLine *old)
 	new->ifImg = old->ifImg;
 	if (new->vi_tail != old->vi_tail) {
 		/* someting wrong */
+		fprintf(stderr, "Error during evaluating TXL line\n");
 		controlled_exit(0);
 	}