I have just started using Duplicati with B2 (free tier just to test). Initial backup of went well. After about the third backup on one day the 1 GB free download quota is exceeded:
Failed to process file duplicati-20180223T230000Z.dlist.zip.aes => System.Exception: 403 - download_cap_exceeded: Cannot download file, download bandwidth or transaction (Class B) cap exceeded. See the Caps & Alerts page to increase your cap. at Duplicati.Library.Main.BackendManager.GetForTesting(String remotename, Int64 size, String hash)
After this, every backup fails with “Unexpected number of remote volumes detected: 0”. In the log these are preceeded by lots of SQLite UNIQUE constraint errors.
This first happened yesterday. After a delete and rebuild of the database, backups started working again but after a frew backups quota is exceeded again and backups start to fail again.