Referencing snapshot on <client> for path "home" failed: FAILED

The incremental backup on my Linux Mint client is hung. The final message in the log file says:

Referencing snapshot on [client name] for path “home” failed: FAILED"

Incrementals on this machine have apparently not run for weeks, possibly since I installed Wine on July 30. All full backups in recent weeks have failed as well. The logs all end with:

Writing directory metadata to “I:\UrBackup[client name]\250802-0629.hashes\home[user name].wine\dosdevices\c:” failed.

Wine was installed on this system on July 30.

Any suggestions on how to troubleshoot this and get backups running again?

Thanks!

Windows 10 Server version: 2.5.32
Linux Mint client version: 2.5.25.0