So you finally updated to Canada Goose and using your backup archives you are seeing the following issue?
Inspecting Archive...
Scanning Archive Directories...
Skipping unsupported archive: mnt
Correcting Permissions...
Sync Filesystem
Then don’t panic too much. Starting with Canada Goose we now have a modular and expandable archive extraction and creation system that utilising top level folder detection.
What this means is that archives are now simpler to create manually without knowing the MustardOS structure. For now you can extract your archive contents and move them accordingly.
Backup Conversion Method
Installing the following archive (thanks to @arkun and @ImCoKeMaN) will install a specific Backup Archive converter within the Task Toolkit. Allowing on-device conversion.
LegacyBackupScript.muxzip (2.1 KB)
Rename and Restore Method
You can rename the extension from muxzip to muxupd and install that way. However in doing so does not guarantee the contents of the archive will be placed in the correct area due to backend restructure.
Future Compatibility
Moving forward with Canada Goose changes all of your backups, including Catalogue and RetroArch Configuration packages will be compatible with future releases.