Entire Computer Freezes when removing Better Touch Tools Accessibility Permissions

When removing Better Touch Tool Accessibility permissions in System Preferences while BTT is running, entire machine becomes unresponsive. Only way to solve is to Hard Shutdown (hold power button until computer shuts off.)

Affected input device (e.g. MacBook Trackpad, Magic Mouse/Trackpad, Touch Bar, etc.):
Entire System

Device information:

  • Type of Mac:
    MacBook Pro 15in 2018
  • macOS version:
  • BetterTouchTool version: (please post the exact version - not just "the latest one")
    Additional information (e.g. StackTraces, related issues, screenshots, workarounds, etc.):

unfortunately it’s a bug in catalina. In the latest BTT alpha I have added some code that kills all relevant system services and restarts BTT if it recognizes Accessibility permissions have been removed (after a few seconds). I hope this will workaround the macOs bug

I have the same problem and it will affect my subscription renewal decision. Because of this issue, I feel not secure enough. Furthermore, I could not find any other app has the same issue, a complete system freeze. Can you please share a reference link that shows it is an Apple related bug but not a BTT specific bug?

The current versions of BTT will try to recognize the system freeze and start some mitigation to workaround the issue, so it should unfreeze after a few seconds.

The easiest way to prevent this is to quit BTT before removing it from the Accessibility list.

I don’t know of any public reference, but if you are a programmer just create an app with intercepting keyboard and mouse cgeventtaps and you‘ll be able to reproduce the issue :wink:

https://stackoverflow.com/questions/60334157/macos-application-hangs-when-using-nsdistributednotificationcenter-and-cfrunloop seems related