Maintenance for the week of May 13:
• [COMPLETE] ESO Store and Account System for maintenance – May 14, 9:00AM EDT (13:00 UTC) - 12:00PM EDT (16:00 UTC)
Obvious first... you did uninstall the old AutoCategory, right?
After that, if you have not done this... delete the "AutoCategory.lua" from the SavedVariables directory and see if that works. You will have to redo any categories that you have, but the upgrade instructions mention doing this.