Cannot proceed - another task needs to finish using the Storage Vault first.
Locked by this device (PID #XXXXX) since XXXX-XX-XX XX:XX:XX (XmXs ago)
The other task is still actively running: must wait until it completes.
The retention encountered a problem (exit status 1)
Appears due to a previous backup job not yet being completed on another device sharing the same username.
The message is about the retention pass which checks old backup versions, and is not related to the backup of your data.
The status of your backup job is listed at the top of the log, and if the backup is ok, will show Backup job saved.
You can see what backup jobs are still running by going in to the Backup Intelligence desktop client or using the web interface at https://bi.ceejay.com/
In the web interface:
Click on the history tab for the drop-down menu and choose Job History
You will then be taken to the job history page. When on this page type "Running" in the filter box. If in the started column the job started > 2 weeks ago please restart all devices on the account and restart the backup.
This will clear this lock message.
Locks are also automatically cleared after a short while, when the job is finished or when a device is cleanly shutdown or when devices are restarted.