The instructions you have for creating a VM using Mojave from the recovery partition appears to be out of date. These instruction are at this URL: https://kb.parallels.com/en/124786. The problem is that Apple has apparently turned off the server that downloads the recovery software when using the recovery partition ("Recovery server not found"). Fortunatley I found a backup installer file for Mojave on another one of my Mac's Time Machine drives so I was able to install it from an image file. Just wanted to give you guys a heads up to please update that web page so that others do not spend time trying to figure out why the install is not working from the recovery partition.