12 Warnings in total (not all warnings are listed here because of duplicate or same warning)
2023-08-30 07:06:17 +08 - [Warning-Duplicati.Library.Main.Controller-UnsupportedOption]: The supplied option --auth-username is not supported and will be ignored
2023-08-30 07:08:22 +08 - [Warning-Duplicati.Library.Main.Operation.Backup.MetadataGenerator.Metadata-MetadataProcessFailed]: Failed to process metadata for "D:\$RECYCLE.BIN\S-1-5-18\", storing empty metadata
Unsupported option: this usually happens when the backup has been first setup with a given backend and changed to another backend, the second one not supporting an option that was used with the first.
Edit the backup, go to page 2 (Destination), click advanced options and then remove the extra option (if it’s not possible, try to select the three dots option ‘edit as text’)
Failure to process metada: this happens because you selected a whole drive and this includes system directories that are off limits. Add a filter to exclude them in page 3 of backup configuration.
The unsupported username is hidden on the backup destination settings. You need to switch back to a backend that has username and password, remove it and then switch back. (There is a PR to fix that).