Index: trunk/src_plugins/mincut/rats_mincut.c
===================================================================
--- trunk/src_plugins/mincut/rats_mincut.c	(revision 26571)
+++ trunk/src_plugins/mincut/rats_mincut.c	(revision 26572)
@@ -230,13 +230,17 @@
 		if (o->term != NULL) {
 			pcb_subc_t *sc = pcb_obj_parent_subc(o);
 			if (sc != NULL) {
-				pcb_net_term_t *t = pcb_net_find_by_refdes_term(&PCB->netlist[PCB_NETLIST_EDITED], sc->refdes, o->term);
-				if (t != NULL) {
-					if (t->parent.net == Snet)
-						gr_add_(g, n->gid, 0, 100000);
-					else if (t->parent.net == Tnet)
-						gr_add_(g, n->gid, 1, 100000);
+				if ((sc->refdes != NULL) && (o->term != NULL)) {
+					pcb_net_term_t *t = pcb_net_find_by_refdes_term(&PCB->netlist[PCB_NETLIST_EDITED], sc->refdes, o->term);
+					if (t != NULL) {
+						if (t->parent.net == Snet)
+							gr_add_(g, n->gid, 0, 100000);
+						else if (t->parent.net == Tnet)
+							gr_add_(g, n->gid, 1, 100000);
+					}
 				}
+				else
+					pcb_message(PCB_MSG_WARNING, "Ignoring subcircuit %ld connecting to a net because it has no refdes;\nplease use the nonetlist flag on the subcircuit to suppress this warning\n", sc->ID);
 			}
 		}