Issue with application running on macOS in VM

I am an application developer, and have an app which does not display its main window when running on macOS on a VM. It works just fine on physical hardware, but in some VM configurations (including a newly-deployed VM), it will not ever display the main window. It only happens on SOME VMs, however - and we have isolated the issue to only happening when the following configuration is set in the config.pvs file:

Code:

<Video VideoMemorySize_patch="1" ApertureOnlyCapable_patch="2" dyn_lists="" NativeScalingInGuest_patch="">
   <Enabled>1</Enabled>
   <Type>0</Type>

Changing the Type to 2 resolves the issue for us:

Code:

<Video VideoMemorySize_patch="1" ApertureOnlyCapable_patch="2" dyn_lists="" NativeScalingInGuest_patch="">
   <Enabled>1</Enabled>
   <Type>2</Type>

This is clearly an issue with my application itself - however, I'm at a loss as to how to resolve it. Is there any information you can provide around what the difference between <Type>0</Type> and <Type>2</Type> might be so that we can use that as a jumping off point for our investigation? Additionally, is there a UI control in Parallels Desktop that we can toggle/change in order to easily set up our VMs with change (rather than manually modifying the pvs file)? Alternatively, is there a prlctl command that can be used to configure it as such so we can script the fix on our build/test VMs while we continue to investigate the issue on our end?

 

As a followup, it looks like running this command sets <Type>0</Type>:

prlctl set <VM-NAME> --video-adapter-type parallels​

And running this command sets <Type>2</Type>:

prlctl set <VM-NAME> --video-adapter-type apple​

So - while I thought this was originally an issue with my application, it actually appears to likely be an issue with the parallels (CPU-based) video adapter as opposed to the optimized apple-provided virtual video adapter.

 

Do you run this prlctl command from the host OS or the VM?
Where do you get "VM-NAME"?
I have a problem with the Preview app showing a blank window when I open image files in the VM (OS X 10.6). I'm wondering if our problems may be related.