It is not possible to restore backup
Failed to restore the VM: The restore command for the "myvm" virtual machine failed with code 3 ("Write error"). Try to restore the virtual machine again. If the problem persists, contact the Parallels support team for assistance.
Incremental backup of resized virtual machine was created. You can experience this issue in following case:
Create full backup of VM
Resize its disk
Create incremental backup
Try to restore incremental backup
To workaround this issue, create new full backup every time you resize your virtual machine's disk.