While testing out older versions of a Cocoa app — Smultron, a developer text editor which used to work great but now it’s very buggy — I stumbled upon the error:
“The managed object model version used to open the persistent store is incompatible with the one used to create the persistent store”
Apparently this is a Core Data error. To fix it you will have to remove some files Core Data builds, which are usually stored in ~/Application Support/. Differently from what mentioned elsewhere, they are not always XML files. In the case of Smultron they looked like binary files named Smultron*.smultron.
For free apps that are installed via drag and drop (no installer) it’s probably safe to wipe out the whole $HOME/Application Support/APPNAME folder contents. It wasn’t there the first time you launched the app after all. However, payed apps may install license info there, and apps with installers may install other stuff there as well, so one must be careful.
In my case, I removed the whole content of ~/Application Support/Smultron and the error disappeared once I relaunched the app.
GOTO 0 