Since updating to Mountain Lion I've been unable to use my TimeMachine volume on my QNAP TS412 NAS (firmware 3.7.1 Build 2012615). I just get the following while attempting to connect to the TM volume: Console give the following error: Code: com.apple.backupd: Backup failed with error: 19 I've so far tried renaming my Mac as well as starting afresh with the TimeMachine configuration on the NAS itself, but still get the same error. TM sees the volume (sparse bundle) on the NAS and I can select it as the desired backup volume, but TM simply cannot proceed with the backup. Anyone know how to fix this? Thanks.