To further analyse file verification errors a client debug log since the last known good file backup including change journal information is needed. You can get this by creating the files "large_log_rotation", "usn_logging_enabled" and "debug_logging_enabled" in C:\Program files\UrBackup. This has the advantage that the debug settings do not get reset by updates. Alternatively you can unpack this zip file to C:\Program files\UrBackup enable-extensive-debugging.zip . The new debug logging settings come into effect after a service restart.