If you don’t use M:\ it’s irrelevant, it’s an exception and lists the path where it was compiled, which is M:\ on our build servers, the relevant part to you is /api/v3/diskspace: value [\SEVERNAME\TV Shows Ended\Valor] is not a valid *nix path. paths must start with /
Which is because you have a Windows path in the DB, which my guess would because you’re attempting to use a backup from a Windows system on the QNAP, which is not supported. You can go Linux to Linux or macOS, but you can only go Windows to Windows unless you’re willing to deal with issues and fix them yourself within the DB.