Currently got a problem where when the game loads up the issue of "Unknown pixel format" comes up and the game black screens. Tried going into choose renderer and it only gives one option. any known ways to solve this issue?

It will be help you.

"The fix for this was moving the Cavedog folder to the desktop."

It might be worth looking at the settings for your display in both your OS and GPU control panel.
Make sure anything related to colour formats is set to RGB.