Comment 5 for bug 1725941

introduced by optional-hot-corner.patch

fix:

diff --git a/extensions/apps-menu/extension.js b/extensions/apps-menu/extension.js
index adc77a4..939a07c 100644
--- a/extensions/apps-menu/extension.js
+++ b/extensions/apps-menu/extension.js
@@ -240,17 +240,21 @@ class ApplicationsMenu extends PopupMenu.PopupMenu {
     }

     open(animate) {
- this._button.hotCorner.setBarrierSize(0);
- if (this._button.hotCorner.actor) // fallback corner
- this._button.hotCorner.actor.hide();
- super.open(animate);
+ if (this._button.hotCorner) {
+ this._button.hotCorner.setBarrierSize(0);
+ if (this._button.hotCorner.actor) // fallback corner
+ this._button.hotCorner.actor.hide();
+ super.open(animate);
+ }
     }

     close(animate) {
         let size = Main.layoutManager.panelBox.height;
- this._button.hotCorner.setBarrierSize(size);
- if (this._button.hotCorner.actor) // fallback corner
- this._button.hotCorner.actor.show();
+ if (this._button.hotCorner) {
+ this._button.hotCorner.setBarrierSize(size);
+ if (this._button.hotCorner.actor) // fallback corner
+ this._button.hotCorner.actor.show();
+ }
         super.close(animate);
     }