Please follow the below steps.
> Launch Lightroom
> Click on Edit > Preferences (In Windows)
Lightroom > Preferences (In Mac)
> Click on the Performance Tab
> Uncheck the option Use Graphics Processor
> Relaunch Lightroom and check for the issue.
Also please mention which version of Lightroom you are using?
Which operating system are you using?
I am using LR 5.7 on a Windows 7 PC.
When I click on Edit / Preferences I don't see a Performance tab.
So how do I get to graphics processor?