"Sync Failed. After syncing, the collection was in an inconsistent state."
To fix this problem, you need to check the collection with the computer version of Anki. If you have reviews in AnkiMobile that you don't have on your computer, please see the "from mobile device to computer" instructions for how you can export your AnkiMobile progress to the computer version: http://ankisrs.net/docs/am-manual.html#itunes-import/export
After that, please run:
- Tools>Maintenance>Check Database
- Check the Preferences>Network>On next sync, force changes in one direction box
- Sync your other devices, and choose to download.
The problem should then be fixed. For those curious as to why this has started happening, AnkiWeb recently started detecting some errors in your collection that it was not noticing before. The most common cause of these errors was pressing the 'preview' button in the add cards window when there's no text on the fields, which generated an empty note with no cards in previous AnkiMobile releases. The bug no longer occurs in the currently available version, but if you pressed the preview button in previous AnkiMobile versions, the empty notes may still be lurking in your collection.