"Live cannot access the undo history file and is switching to a memory based undo"

To resolve the Ableton Live error message:

"Live cannot access the undo history file and is switching to a memory based undo"

1. Close Live
2. Locate the files Undo.cfg (Live 8 and earlier: Undo folder) and Preferences.cfg, and move these to the trash.

To find these files, navigate to the following hidden folders. Here's how to access hidden folders.

Windows

\Users\[username]\AppData\Roaming\Ableton\Live x.x.x\Preferences\

Mac

/Users/[username]/Library/Preferences/Ableton/Live x.x.x/