Strange "shadows"

[≡(Light)≡]

I have this problem in all maps, but only when looking at certain parts of the map. Help.

https://www.youtube.com/watch?v=xCalhAYbMyg

[Mst]

Possibly the strangest thing i have ever seen cos i know sometimes in this map i see shadows cover like  the majority of the map and then dissapears but as for this you might wanna try reinstalling graphics card drivers or reinstalling ddons for gmos entierly

[Young Skippy]

The possible solution could be to change your "Shadow Detail", this is a common problem.

[≡(Light)≡]

It was Overwolf for some reason. I disabled it and now everything works fine. Hopefully they'll fix it.

[G-TIX]

it is overwolf...i have the same in L4D2

[Generic User #1456]

it’s the shadows in your head light...