After following the installation.md instructions, I was presented with the following error:

Implementation of the USB 2.0 controller not found!
Because the USB 2.0 controller state is part of the saved VM state, the VM cannot be started. To fix this problem, either install the 'Oracle VM VirtualBox Extension Pack' or disable USB 2.0 support in the VM settings.
Note! This error could also mean that an incompatible version of the 'Oracle VM VirtualBox Extension Pack' is installed (VERR_NOT_FOUND).

Result Code: | NS_ERROR_FAILURE (0x80004005)
...

After installing the extension pack, things worked perfectly fine. Unless USB 2.0 support is necessary, perhaps you could disable it before creating the .ova and just re-upload to Google Drive (and update the hashes).

Side note: If you choose to update the instructions.md instead of asking that people install the extensions, brew had a cask for this that worked fine (relevant to macOS systems - brew cask install virtualbox-extension-pack), but there are other ways to install (There are some details in the User Manual) that you may want to point people to.

Good morning,
I just downloaded and run Griffon in prder to test "superset".
Unfortunately start up script is not wornking
path /home/griffonuser/anaconda3//bin/superset run -p 8090 is not exining.
can you help me to fix start-up script?
Is it possible to update superset?
thanks
Walter