diff --git a/create_ap b/create_ap
index 6b3b5ca..9cf408f 100755
--- a/create_ap
+++ b/create_ap
@@ -1245,6 +1245,7 @@ trap "cleanup_lock" EXIT
 
 if ! init_lock; then
     echo "ERROR: Failed to initialize lock" >&2
+    echo "Try to remove /tmp/create_ap.all.lock" >&2
     exit 1
 fi