Hi,
I’m getting for one server this kind of errors many times whenever a backup is running.
What is the reason for these errors? Files with the name .dir_metadata doesn’t exist on that client server.
I know this is 2+ years old, but I had this issue and I was able to resolve it. I made sure to re-enable Full Backups for the client (I had previously checked the Disabled checkboxes for full backups, and was only running Incrementals), and ran a Full Backup… that was it. This fixed multiple clients I had with this issue.