Broken iCloud Backups

Somewhere around July 30th, my iCloud backups started failing. I got the ‘Backup cannot be completed message’. I am running a beta of iOS 6, so I assumed it had something to do with that. After some research, I discovered it in fact had nothing to do with iOS 6. It took some trial and error, but here is how to solve it:

  1. Turn off iCloud backups and delete any partial backups
  2. Make a good iTunes backup (just for kicks)
  3. Turn iCloud backups back on, but turn off every single application
  4. Make a full backup to iCloud
  5. Assuming step 4 works, turn on a few applications
  6. Make another backup
  7. Once it fails again, further test the last set of applications you turned back on.
  8. Once you discover which app it is, figure out a way to delete the application without causing a ton of pain (export data, etc)

On my iPhone, the cultript was Keynote. On my iPad, it was iA Writer.