Accessibility has been completely reworked in Mac OS X 10.9 Mavericks and is quite brittle at the moment. Even after enabling Accessibility for Divvy, you might get this dialog stating that Accessibility is not enabled. This can happen when switching from the demo version of Divvy to the Mac App Store version.
Here is a workaround to solve this issue.
Before You Beginâ¦
Make sure you only have ONE copy of Divvy installed:
Open a new Finder window and type "Divvy" in the search field to find all copies of Divvy. If you find more than one copy, to be safe, Trash all copies and re-download either from our website or from the Mac App Store, whichever you did/will purchase from.
Either download and run this small program or run the steps manually:
1) Quit Divvy and System Preferences if either are running.
2) Launch Terminal.app which is in your /Applications/Utilities folder.
3) Copy and paste the following as a single line into Terminal and press the Enter key; you'll be prompted for your password:
sudo sqlite3 /Library/Application\ Support/com.apple.TCC/TCC.db 'delete from access where client like "%divvy%"'
4) Restart your Mac then follow the steps to enabling Accessibility for Divvy like normal.