Viewer in Developer isn't working

[buddym30284285]

How do I fix the below issue?

[Marianne-Deiters]

You could give more information so we can help you. It may be that you need to update the video card driver. 
Uncheck the support for the graphics processor in the Preferences to test it.

[buddym30284285]

It was working yesterday and then last night it just stopped working.  My video card driver works just fine.  I can use another version of lightroom and it works, but I prefer the classic version of lightroom for editing.  

[42des]

I got a great hint here on Monday. Go to settings an choose manual graphic settings and then disable GPU. Good luck! 

Ina