ODK Aggregate VM error in VirtualBox

1. What is the problem? Be very detailed.
I follow the following steps: https://docs.opendatakit.org/aggregate-vm/
When starting aggregate VM in VirtualBox, I receive an error (see below for screenshot). Hence, step number 5 of the manual never occurs.
2. What app or server are you using and on what device and operating system? Include version numbers.
I downloaded the latest version of ODK aggregate (v2.0.5) and use the Virtual Box 6.0.14, recently repaired/updated.

3. What you have you tried to fix the problem?
I have no clue how I can fix the error. I removed aggregate from VirtualBox and opened the .ova file again to try to start it again - this did not help.

4. What steps can we take to reproduce the problem?
Download the same software and try to start aggregate in VirtualBox.

5. Anything else we should know or have? If you have a test form or screenshots or logs, attach below.