Referencing snapshot on X for path Y failed

Hello

We have urbackup 2.0.33 and a Mac client. Backup for this client is always failing and on every log file these lines are together:

Info

22/09/16 08:37
Referencing snapshot on “client_hostname” for path “some_file” failed: FAILED
Errors

22/09/16 08:37
Error getting file metadata. Errorcode: SOME_ERROR (ERROR_CODE)

Always first error in log is preceded with a line “referencing snapshot”

Thanks in advance for any help.
If needed ask for any further info.

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