Distortion when applying RGB Curves

Hi. 

I am new to Premiere  Pro. Love it so far but i cant figure out what has happened for this problem to occur. 

The two picutres below are before and after applying the RGB curve. HSL Secondary does the same thing. Basic correction works fine.

I have tried to reinstall Pr and to no avail. 

Recently I have updated my graphics card driver, but that is about it. 

My Specs:

i7-7700K CPU @ 4.20GHz 4.20

16GB RAM

NVIDIA GeForce GTX 1060 6GB

Windows 10 Home

I have no idea what is going on. Can someone help please or point me in the right direction?