From 153a4bca42e473d70670b844eac62be8daf7b604 Mon Sep 17 00:00:00 2001
From: Jan Prochazka <jan.prochazka@gmail.com>
Date: Thu, 8 Apr 2021 19:56:36 +0200
Subject: [PATCH] fix

---
 packages/web/src/utility/createActivator.ts | 22 +++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/packages/web/src/utility/createActivator.ts b/packages/web/src/utility/createActivator.ts
index ce3c975c2..5d94f4207 100644
--- a/packages/web/src/utility/createActivator.ts
+++ b/packages/web/src/utility/createActivator.ts
@@ -21,17 +21,19 @@ export default function createActivator(name: string, activateOnTabVisible: bool
   let tabVisibleValue;
 
   onMount(() => {
-    const unsubscribeTabVisible = tabVisible.subscribe(value => {
-      tabVisibleValue = value;
-      if (activateOnTabVisible) {
-        activate();
-      }
-    });
-    invalidateCommands();
+    if (tabVisible) {
+      const unsubscribeTabVisible = tabVisible.subscribe(value => {
+        tabVisibleValue = value;
+        if (activateOnTabVisible) {
+          activate();
+        }
+      });
+      invalidateCommands();
 
-    return () => {
-      unsubscribeTabVisible();
-    };
+      return () => {
+        unsubscribeTabVisible();
+      };
+    }
   });
 
   const activate = () => {