BTT crashes on startup after update, macOS 26.0.1. Log shows: migrate|fixing uuids2 → save → crash with
NSSQLiteErrorDomain=1. All versions (6.217, 6.311) affected.
Sounds like a database corruption issue, but is there a reason why you are on on macOS 26.0.1? (that version of macOS Tahoe was super buggy)
▎ "I'm on macOS Tahoe 26.0.1 because it's showing as the current version in Software Update with no newer
version available."
▎ Sorry for the misleading post — the issue was not specifically related to the BTT update. I'm running
macOS Tahoe 26.0.1 (25A362), which apparently has known bugs affecting CoreData/SQLite. I just found macOS
Tahoe 26.4 and am currently downloading it. Will report back after the update whether BTT works again.
That's unfortunate, probably another bug in that Tahoe version 
the current version is already 26.4 (which is way more stable).
Possibly try pressing cmd+r while the update window is open to refresh.
However this most likely also won't fix the corrupted database. Unfortunately you might need to reset BTT. In a first step you can use this terminal command to move the BTT configuration to a backup folder - then at least BTT will launch again (with an empty configuration though)
mv -n ~/Library/Application\ Support/BetterTouchTool ~/Library/Application\ Support/BetterTouchTool_backup