For the last month I've been having issues with iCloud backup on my iPad. The auto backups weren't happening, and even if I attempted a manual backup, I would get an error that said "There was a problem completing the backup." After pouring over what felt like hundreds of pages, I finally found a solution that worked! Here is the solution from this Apple forum page
I finally have a complete back-up of my iPad2 to iCloud. This is what I did...After I turned off the backups for most of the apps (especially the largest ones) my iPad was able to successfully back up to iCloud. I am now in the process of slowing adding the apps back in a few at time.
- Signed out of iCloud, then shut iPad down completely. After launching it, I signed back into iCloud. Pushed Back Up Now button and it backed up for a while, but never completed.
- Go to Manage Storage, Selected iPad, then turned off all backup options. When back to Back Up Button and after about 20-minutes...I had a complete back-up.
- I've gone back and started turning back on the apps a few at a time, then selecting Back Up and continue to get complete back-ups.