Hey guys, i changed the resolution in the nglider to my native 1920 1080, im not sure if thats whats causing it but using a weapon or going through doors i will have white lines outlining my screens borders, like someone traced around the frame. any ideas what that might be? thanks alot

I have the same problem (When I do a right click with the Gel'ziabar stone equipped, or when a phantom appears).

I press "Alt + enter" to go into windowed mode, then a second time to return in full screen, and the lines disappear.
If someone has a better solution i'am interested.

Are you using nGlide? I'm having the same issue.

I think the issue doesn't happen with Direct3D.

Going to the pause menu seems to be enough to fix it for me...

All I could find out is that it seems to be related to the graphics card. When I changed from my Nvidia main card to the internal Intel HD, it stopped (but performance is terrible).

I managed to fix this problem with the new Widescreen Patch for Undying (uses dgVoodoo). Instructions are [https://www.pcgamingwiki.com/wiki/Clive_Barker%27s_Undying#Exemplary_Setup_of_GOG_version here].