Shader file common.fh needed amending, as per comments here: https://bbs.archlinux.org/viewtopic.php?id=258020

I've played hundreds of hours of this on GOG and it's my second favourite game of the entire series, X4 now having taken top spot in my affections. I've just left comment on Egosoft boards that they've been ignoring a very simple fix for four years now, caused by Nvidia drivers becoming stricter about error messages, that players like me are still encountering. But for anyone reading once the shader file is tweaked (you delete two characters each from the ends of lines 574 and 622 of the file) the game runs amazingly well.