diff -u -r cooledit-4.0.0/widget/focus.c cooledit-4.0.0/widget/focus.c
--- tmp/cooledit-4.0.0/widget/focus.c	2019-12-16 12:08:34.000000000 -0600
+++ cooledit-4.0.0/widget/focus.c	2020-03-17 10:32:12.222913504 -0500
@@ -441,6 +441,8 @@
 CWidget *CNextFocus (CWidget * w)
 {
     int i, j;
+    if (!w)
+	return 0;
     i = j = find_next_child_of (w->parentid, w->winid);
     for (;;) {
 	if (!i) {
