Index: alien_formats/altium/pcbdoc_bin.c
===================================================================
--- alien_formats/altium/pcbdoc_bin.c	(revision 35457)
+++ alien_formats/altium/pcbdoc_bin.c	(revision 35458)
@@ -125,6 +125,10 @@
 		len = read_rec_tlb(fp, tmp, &rectype);
 		if (len <= 0)
 			return len;
+		if (rectype != 4) {
+			rnd_message(RND_MSG_ERROR, "Tracks6 record with wrong type; expected 4, got %d\n", rectype);
+			continue;
+		}
 		if (len < 45) {
 			rnd_message(RND_MSG_ERROR, "Tracks6 record too short; expected 45, got %ld\n", len);
 			continue;