Restore manually a windows 10 Laptop

I’m trying UrBackup right now. For testing I have set up a server with OMV and run Urbackup as docker image.
After I made some backups of an old laptop, I wanted to see if the restore works.
I destroyed the partition of the boot drive and boot the ‘UrBackup Restore CD’ from a USB stick.
What first struck me was that only the C and D drives were offered. The SYSVOL drive was missing.
I restored C and D and booted the laptop, but it didn’t work. After a little research, I realized that a full recovery doesn’t work automatically, but you have to do it manually. For this I have tried the following instructions
https://forums.urbackup.org/t/restore-images-manually-mounted-via-smb/4180

In the manual only vhd files are mentioned. But my backups are compressed as a vhdz file.
Now I always get the error message ‘ERROR: Could not open MBR File’ when accessing the mbr image.
Do I have to unzip the images first? Or what could I do wrong?