since a few days the automatic iCloud backup didn’t complete (during night, connected to WLAN and power); even started by hand it ended with “couldn’t complete” (or so).
After checking some preferences it seems I found the issue: the whole DTTG database seems to be part of the backup. I saw > 8 GB of space needed to be backed up. If I compare this with Evernote (all data replicated to the device, many gigabytes) only a few hundred megabytes are needed to be backed up. I’ve turned DTTG backup to OFF - now the backup process completes.
Is this an App internal setting/configuration what data should be part of iCloud backup? If yes, it may make sense to change this within the App code.
FYI, I have experienced this issue too. My iCloud backups were failing on both iPhone and iPad. My database size is only around 2 GB. Before I narrowed the cause down to DTTG I had escalated it to Apple engineering and they were unable to figure it out. Finally I turned off DTTG iCloud backups as a troubleshooting step and that fixed the problem.
Since I am basically backing up to the sync store an Dropbox the iCloud backup is redundant so I am not to worried about not having it. But the unfortunate thing is that my backups were failing silently. If I had not gone and checked I would have no idea that my iPhone was not being backed up which could have been bad if I had needed to use those backups!
I will add on to list of those affected by this. My DB file was showing 5GB. The iphone backup was silently failing with the less-than-helpful ‘Could not complete backup’ message.