Noticed another thing that is different from the original Hexen 2 or the Hammer of Thyrion port.

Getting hit - the screen is supposed to very lightly flash red whenever you get hit. This is not present in the GOG version.

Picking up items other than Crystal Vials - the screen is supposed to very lightly flash white/yellow when picking up items other than Crystal Vials. This is not present in the GOG version.

Being under water - The screen is supposed to show everything covered by a slight brown-ish hue to indicate being underwater. Currently in the GOG version, this is not present (making underwater look exactly like outside of water) and while being underwater, the geometry gets randomly distorted (does not happen in the original Hexen 2).

That being said, does anybody know how to get these back in the GOG version? Especially the lack of feedback when getting hit is noticeable.

Tried deleting the file but it just made the graphics much worse and the screen effects are still missing.

It's not a fault with the GOG version, but with the official patch. If you install Hexen 2 directly from the CD, everything works fine.
The screen flashes yellow when you pick up items and red when you get hit, Necromancer's Magic Missiles have transparency and so on...
Now install the 1.11 patch and it's exactly like the GOG version. No screen flashing, Magic Missiles are a black box, etc.

Sadly, the developers themselves messed up at some point. But I understand you, it bothers me as well.

_ As this topic is about missing effects, I would like to point out that GLHexen suffers from the same issues as GLQuake - the lack of fullbrights and overbright lighting.
The difference is obvious in many places.
There are a few other issues on top of that, like the transparency effect of certain barriers or teleporters. Overall, OpenGL mode lacks a lot of graphical information that software mode displays just fine.

Thanks for the explanation. I played the game with Hammer of Thyrion where it's luckily working fine. I was mostly making this thread to make people aware that there is a difference. The most obvious one is the under water thing. It looks like you're just floating in space without the effect.

Can you try Windows XP Sp3 compatibility mode for GLH2.exe?