Index: trunk/psModules/src/concepts/pmConceptsRead.c
===================================================================
--- trunk/psModules/src/concepts/pmConceptsRead.c	(revision 11865)
+++ trunk/psModules/src/concepts/pmConceptsRead.c	(revision 12285)
@@ -76,6 +76,11 @@
     }
     if (!parsed) {
-        psError(PS_ERR_UNEXPECTED_NULL, false, "Unable to parse concept %s\n", spec->blank->name);
-        return false;
+        if (spec->required) {
+            psError(PS_ERR_UNEXPECTED_NULL, false, "Unable to parse concept %s\n", spec->blank->name);
+            return false;
+        } else {
+            psWarning("Unable to parse concept %s, but concept not marked as required.\n", spec->blank->name);
+            psErrorClear();
+        }
     }