Index: src/libcschem/util_wirenet.c
===================================================================
--- src/libcschem/util_wirenet.c	(revision 10373)
+++ src/libcschem/util_wirenet.c	(revision 10374)
@@ -1024,7 +1024,8 @@
 			wn = (csch_cgrp_t **)vtp0_get(new_wirenets, seg, 0);
 			if ((wn == NULL) || (*wn == NULL)) {
 				wn_ = csch_wirenet_new_from(sheet, line->hdr.parent);
-				wn_->hdr.selected = line->hdr.parent->hdr.selected;
+				if (line->hdr.parent != NULL)
+					wn_->hdr.selected = line->hdr.parent->hdr.selected;
 				vtp0_set(new_wirenets, seg, wn_);
 				wn = &wn_;
 			}