My server in use CentOS 7.6, urbackup v2.3.7 (storage zfs). Client in use Windows Server 2008R2, urbackup v2.3.4 (storage ntfs)
From 22 February there was such an error.
2019-02-26 08:01:00: ERROR: Creating snapshot of “E:\СО” failed
2019-02-26 08:01:00: ERROR: Cannot create snapshot of file system with type
2019-02-26 08:01:00: ERROR: Creating snapshot of “СО” failed.
2019-02-26 08:01:00: ERROR: Cannot access path to backup: “E:\СО” Errorcode: 2 - No such file or directory
2019-02-26 08:01:00: WARNING: Hint: Directory to backup (“E:\СО”) does not exist. It may have been deleted or renamed. Set the “optional” directory flag if you do not want backups to fail if directories are missing.
2019-02-26 08:01:00: ERROR: Indexing files failed, because of error
2019-02-26 08:01:00: ERROR: Constructing of filelist of “WSTR02” failed: error - index error
2019-02-26 08:01:10: ERROR: Backup had an early error. Deleting partial backup.
2019-02-26 08:01:11: WARNING: Exponential backoff: Waiting at least 10h 40m before next file backup
Server and client are in different segments of the local network.