So I've had problems with DOSBOX graphics setup before, specifically when switching a graphic mode.
Also, to a layman DOSBox Configurator, at least the graphics modes are confusing. I'm not sure what is what, surface, overlay etc.
So playing around with these, some work, some don't. One caused what seems to be a fault with the graphics card and now DOSBox has been blocked from accessing graphics hardware.
Now no DOSBox games work, no screen, it's whited out. I tried to fix this error using multiple "solutions" online, one was to reinstall the basic Microsoft display adapter, which works, but in turn seems to delete my current Nvidia driver and I have to reinstall that. After Nvidia is reinstalled the issue is back again.
This is really annoying does anyone know a fix or has encountered this issue before?

Dosbox should fix their software so it doesn't create severe problems such as these.

Beyond changing the configuration to the default... maybe modifying the stretch/ratio configuration slightly.

Can't access display hardware? I know you might get this in Linux where SvgaLib had a bit about needing superuser to access and change the video mode (which it then immediately released root access), but this?

Hmmm... Dosbox likely uses simpler DirectX (DX9?) or SDL. I forget which.

Well got it working. Using the "Open GL" graphics mode in the DosBox configurator for everything now. Seems to work.
DosBox really ought to add some tool tips to the different options on the configurator, would make things so much easier and not have people run into issues like this.