Index: generic/nsf.c
===================================================================
diff -u -rd9a6fbf56b9559455a3b57a31dcc76b388b2b1ab -rb9e39fb7a7a01c2b07a112700d42060eadde4d8d
--- generic/nsf.c	(.../nsf.c)	(revision d9a6fbf56b9559455a3b57a31dcc76b388b2b1ab)
+++ generic/nsf.c	(.../nsf.c)	(revision b9e39fb7a7a01c2b07a112700d42060eadde4d8d)
@@ -12702,13 +12702,17 @@
                      Tcl_Interp *interp, int objc,
                      Tcl_Obj *CONST objv[]) {
   AliasCmdClientData *tcd = (AliasCmdClientData *)clientData;
-  NsfObject *self = tcd->object;
+  NsfObject *self = GetSelfObj(interp);
   CONST char *methodName = ObjStr(objv[0]);
+  if (!self) {
+    return NsfPrintError(interp, "Cannot resolve 'self', "
+			 "probably called outside the context of a Next Scripting Object");
+  }
 
-  assert(tcd->object == GetSelfObj(interp));
+  assert(tcd->object == self);
 
   if (self == NULL) {
-    return NsfDispatchClientDataError(interp, self, "object", 
+    return NsfDispatchClientDataError(interp, tcd->object, "object", 
 				      Tcl_GetCommandName(interp, tcd->aliasCmd));
   }
 
@@ -15423,7 +15427,7 @@
   NsfObject *self = GetSelfObj(interp);
   if (!self) {
     return NsfPrintError(interp, "Cannot resolve 'self', "
-			 "probably called outside the context of an Next Scripting Object");
+			 "probably called outside the context of a Next Scripting Object");
   }
   /* fprintf(stderr, "Colon dispatch %s.%s\n", ObjectName(self),ObjStr(nobjv[0]));*/
   return ObjectDispatch(self, interp, nobjc, nobjv, NSF_CM_NO_SHIFT);
@@ -15880,7 +15884,7 @@
 
   if (!self) {
     return NsfPrintError(interp, "Cannot resolve 'self', "
-			 "probably called outside the context of an Next Scripting Object");
+			 "probably called outside the context of a Next Scripting Object");
   }
 
   if (withLocal) {