Are you trying a file-level-restore for a Windows VM? If so, make sure you have the "ntfs-3g" package installed on your VM running XO.

You should probably be able to fix this issue by installing the ntfs-3g package.

As you mentioned you're running it on a Synology, you can do that in DSM by opening Docker -> Container -> Select your container -> Details -> Terminal and enter the below in the console.

apk update

apk add ntfs-3g

Let us know if it helped.