I'm having this same issue. I think it's from my resolution being too large (5120x1440), but I'm not positive. Wondering if I can manually set it to a lower resolution and Windowed mode to see if it works.

So I installed Verok's patch (the 1.5GB version). It won't let me share the url.

I was still getting the black screen after launching it with GOG Galaxy. I started looking at the files and configs to see if I needed to run it in compatibility or something. I ran the Kain.exe in the game directory and then it popped up a Settings configuration window. From there I was able to set it to Windowed mode and set the resolution. Then the game launched correctly.

I haven't tried it, but I just noticed GOG Galaxy also has some similar settings to configure. If you go to the game settings > Additional Executables > DirectX Settings. Those options may do the same thing, but I'm not going to bother since running the EXE directly is working.

I had this issue too until I installed Verk's GL Wrapper on top of the game. Now everything works absolutely fine and the intros that where only black before appear like the should.

Thanks to both! Fixed with installation of Verk's GL Wrapper.