Nextcloud VM - Daily Backup Wizard

Hi, I just downloaded the 40 GB NC VM for VMWare and installed it on my Windows-Host.
When I come to the Point to install the Daily Backup Wizard from the installation-Script I always end in an error "Unfortunately you have not enough free space on your vgs to create a LVM-snapshot which is a requirement to create a backup script. " I didnt change the VM in any way. What is wrong here? What can Ido?