unfortunately the crashlog is a bit too generic to be helpful.
Could you send the contents of this folder to me? "~/Library/Application Support/BetterTouchTool" (to andreas@folivora.ai). Then I should be able to reproduce this.
You can also try to enable safe mode with this terminal command, this might allow you to access the BTT UI again to delete the trigger that might cause this - although all functionality will be disabled while safe mode is on:
I've activated the SafeMode, But still can't access the BTT UI.
It shows that SafeMode is Active, but nothing.
The BTT window shows for a second and it crashes!