Strange white lines around the map

So, recently I re-installed Garry’s Mod after spending a few months away from the game, loaded up a map and found that a number of odd white lines were coming from the ground, shooting around the map, only visible from certain angles. Thought it was a problem with the map, loaded up gm_flatgrass and gm_construct and found they were appearing there too.

Anyone had this issue before, and if you have, how the hell do you fix it?

It’s not exactly a game breaking bug, but it’s definitely annoying. Looked around for solutions, found an old thread on the Steam forums, garry mentioned it was apparently an issue related to anti-aliasing, so I disabled it, still had the lines everywhere.

Try reinstalling garrys mod and re enabling addons one by one.