diff --git a/src/dump_custom.cpp b/src/dump_custom.cpp
index b2acdbfc51..0e47671bb9 100644
--- a/src/dump_custom.cpp
+++ b/src/dump_custom.cpp
@@ -131,7 +131,7 @@ DumpCustom::DumpCustom(LAMMPS *lmp, int narg, char **arg) :
 
   if (ioptional < nfield &&
       strcmp(style,"image") != 0 && strcmp(style,"movie") != 0)
-    error->all(FLERR,"Invalid attribute in dump custom command");
+    error->all(FLERR,"Invalid attribute {} in dump {} command",earg[ioptional],style);
 
   // noptional = # of optional args
   // reset nfield to subtract off optional args
@@ -238,9 +238,8 @@ DumpCustom::~DumpCustom()
 
   for (int i = 0; i < ncustom; i++) delete[] id_custom[i];
   memory->sfree(id_custom);
-  delete [] custom;
-  delete [] custom_flag;
-
+  memory->sfree(custom);
+  memory->sfree(custom_flag);
   memory->destroy(choose);
   memory->destroy(dchoose);
   memory->destroy(clist);
@@ -909,32 +908,27 @@ int DumpCustom::count()
 
       } else if (thresh_array[ithresh] == Q) {
         if (!atom->q_flag)
-          error->all(FLERR,
-                     "Threshold for an atom property that isn't allocated");
+          error->all(FLERR,"Threshold for an atom property that isn't allocated");
         ptr = atom->q;
         nstride = 1;
       } else if (thresh_array[ithresh] == MUX) {
         if (!atom->mu_flag)
-          error->all(FLERR,
-                     "Threshold for an atom property that isn't allocated");
+          error->all(FLERR,"Threshold for an atom property that isn't allocated");
         ptr = &atom->mu[0][0];
         nstride = 4;
       } else if (thresh_array[ithresh] == MUY) {
         if (!atom->mu_flag)
-          error->all(FLERR,
-                     "Threshold for an atom property that isn't allocated");
+          error->all(FLERR,"Threshold for an atom property that isn't allocated");
         ptr = &atom->mu[0][1];
         nstride = 4;
       } else if (thresh_array[ithresh] == MUZ) {
         if (!atom->mu_flag)
-          error->all(FLERR,
-                     "Threshold for an atom property that isn't allocated");
+          error->all(FLERR,"Threshold for an atom property that isn't allocated");
         ptr = &atom->mu[0][2];
         nstride = 4;
       } else if (thresh_array[ithresh] == MU) {
         if (!atom->mu_flag)
-          error->all(FLERR,
-                     "Threshold for an atom property that isn't allocated");
+          error->all(FLERR,"Threshold for an atom property that isn't allocated");
         ptr = &atom->mu[0][3];
         nstride = 4;
 
@@ -1521,7 +1515,7 @@ int DumpCustom::parse_fields(int narg, char **arg)
         field2index[iarg] = add_variable(name);
         break;
 
-      // custom per-atom floating point vector or array
+      // custom per-atom floating point vector or array = d_ID d2_ID
 
       case ArgInfo::DNAME:
         pack_choice[iarg] = &DumpCustom::pack_custom;
@@ -1533,18 +1527,18 @@ int DumpCustom::parse_fields(int narg, char **arg)
           error->all(FLERR,"Could not find custom per-atom property ID: {}", name);
         if (argindex[iarg] == 0) {
           if (!flag || cols)
-            error->all(FLERR,"Property double vector for dump custom does not exist");
+            error->all(FLERR,"Property double vector {} for dump custom does not exist",name);
         } else {
           if (!flag || !cols)
-            error->all(FLERR,"Property double array for dump custom does not exist");
+            error->all(FLERR,"Property double array {} for dump custom does not exist",name);
           if (argindex[iarg] > atom->dcols[n])
-            error->all(FLERR,"Dump custom property array is accessed out-of-range");
+            error->all(FLERR,"Dump custom property array {} is accessed out-of-range",name);
         }
 
         field2index[iarg] = add_custom(name,1);
         break;
 
-      // custom per-atom integer vector or array
+      // custom per-atom integer vector or array = i_ID or i2_ID
 
       case ArgInfo::INAME:
         pack_choice[iarg] = &DumpCustom::pack_custom;
@@ -1556,15 +1550,12 @@ int DumpCustom::parse_fields(int narg, char **arg)
           error->all(FLERR,"Could not find custom per-atom property ID: {}", name);
         if (argindex[iarg] == 0) {
           if (flag || cols)
-            error->all(FLERR,
-                       "Property integer vector for dump custom does not exist");
+            error->all(FLERR,"Property integer vector {} for dump custom does not exist",name);
         } else {
           if (flag || !cols)
-            error->all(FLERR,
-                       "Property integer array for dump custom does not exist");
+            error->all(FLERR,"Property integer array {} for dump custom does not exist",name);
           if (argindex[iarg] > atom->icols[n])
-            error->all(FLERR,
-                       "Dump custom property array is accessed out-of-range");
+            error->all(FLERR,"Dump custom property array {} is accessed out-of-range",name);
         }
 
         field2index[iarg] = add_custom(name,0);
@@ -1574,6 +1565,7 @@ int DumpCustom::parse_fields(int narg, char **arg)
 
       default:
         return iarg;
+        break;
       }
     }
   }
@@ -1667,13 +1659,9 @@ int DumpCustom::add_custom(const char *id, int flag)
     if (strcmp(id,id_custom[icustom]) == 0) break;
   if (icustom < ncustom) return icustom;
 
-  id_custom = (char **)
-    memory->srealloc(id_custom,(ncustom+1)*sizeof(char *),"dump:id_custom");
-
-  delete [] custom;
-  custom = new int[ncustom+1];
-  delete [] custom_flag;
-  custom_flag = new int[ncustom+1];
+  id_custom = (char **) memory->srealloc(id_custom,(ncustom+1)*sizeof(char *),"dump:id_custom");
+  custom = (int *) memory->srealloc(custom,(ncustom+1)*sizeof(int),"dump:custom");
+  custom_flag = (int *) memory->srealloc(custom_flag,(ncustom+1)*sizeof(int),"dump:custom_flag");
 
   id_custom[ncustom] = utils::strdup(id);
   custom_flag[ncustom] = flag;
@@ -1962,21 +1950,18 @@ int DumpCustom::modify_param(int narg, char **arg)
         if (n < 0)
           error->all(FLERR,"Could not find custom per-atom property ID: {}", name);
         if (argindex[nfield+nthresh] == 0) {
-          if (flag || cols)
-            error->all(FLERR,
-                       "Property double vector for dump custom does not exist");
+          if (!flag || cols)
+            error->all(FLERR,"Property double vector for dump custom does not exist");
           thresh_array[nthresh] = DVEC;
         } else {
-          if (flag || !cols)
-            error->all(FLERR,
-                       "Property double array for dump custom does not exist");
+          if (!flag || !cols)
+            error->all(FLERR,"Property double array for dump custom does not exist");
           if (argindex[nfield+nthresh] > atom->dcols[n])
-            error->all(FLERR,
-                       "Dump custom property array is accessed out-of-range");
+            error->all(FLERR,"Dump custom property array is accessed out-of-range");
           thresh_array[nthresh] = DARRAY;
         }
 
-        field2index[nfield+nthresh] = add_custom(name,0);
+        field2index[nfield+nthresh] = add_custom(name,thresh_array[nthresh]);
         break;
 
       // custom per atom integer vector or array
@@ -1988,20 +1973,17 @@ int DumpCustom::modify_param(int narg, char **arg)
           error->all(FLERR,"Could not find custom per-atom property ID: {}", name);
         if (argindex[nfield+nthresh] == 0) {
           if (flag || cols)
-            error->all(FLERR,
-                       "Property integer vector for dump custom does not exist");
+            error->all(FLERR,"Property integer vector for dump custom does not exist");
           thresh_array[nthresh] = IVEC;
         } else {
           if (flag || !cols)
-            error->all(FLERR,
-                       "Property integer array for dump custom does not exist");
+            error->all(FLERR,"Property integer array for dump custom does not exist");
           if (argindex[nfield+nthresh] > atom->icols[n])
-            error->all(FLERR,
-                       "Dump custom property array is accessed out-of-range");
+            error->all(FLERR,"Dump custom property array is accessed out-of-range");
           thresh_array[nthresh] = IARRAY;
         }
 
-        field2index[nfield+nthresh] = add_custom(name,0);
+        field2index[nfield+nthresh] = add_custom(name,thresh_array[nthresh]);
         break;
 
       // no match