FS-5434 --resolve

src/mod/applications/mod_blacklist/mod_blacklist.c

@@ -271,7 +271,7 @@ SWITCH_STANDARD_API(blacklist_api_function)
 		filename = switch_core_hash_find(globals.files, argv[1]);
 		switch_mutex_unlock(globals.files_mutex);
 
-		if (!bl) {
+		if (!bl || !filename) {
 			switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Unknown blacklist [%s]\n", argv[1]);
 			stream->write_function(stream, "-ERR Unknown blacklist\n");
 			goto done;