Hi! So I installed Shadow of Chernobyl for the first time, played it a little bit. Everything is super smooth and fast. I then made a save game early in the game and I figured I'd install the ZRP mod for the bug fixes. I unpacked the gamedata directory in the SoC folder and edited the fsgame.ltx file. After this I started the game, but I noticed loading my save took much longer than before. After it finally loaded the game is very stuttery.

I installed ZRP 1.07 R5 RC. Am I doing something wrong?

This is a head-scratcher. ZRP makes things run better, normally. The game with ZRP uses less memory than the normal game by itself. Make sure you are not using any compatibility mode. Also try limiting your framerate to 250 or less in your video driver's configuration tool, especially if you have a relatively-recent computer. Using your monitor's preferred refresh frequency is recommended.

Do you have cloud saves enabled? I don't recommend this; if your game or computer crashes, there can be loss of access to all the saves online. And this feature might be slowed down by some interaction with your game using ZRP.

Also, if you have loaded any new features that GOG now supplies (example: the removal of the requirement to give permission to launch the game every time you try to start it -- a good idea), there may be some new incompatibility with ZRP introduced by the changes.

Check to see if any software is running in the background that might interfere with the execution of the game. GOG Galaxy should not cause problems, but the game can be run in standalone mode by downloading a backup copy from GOG, installing this backup copy (not to Program Files! -- see below) and then running the game. It might be that your antivirus is constantly checking the ZRP files as they are loaded during the game's execution.

I don't know what you mean by "unpacked the gamedata directory in the SoC folder". If you didn't just copy over the gamedata folder from the extracted ZRP archive, then I'd suggest removing the gamedata folder and trying again. If you installed to "C:\Program Files (x86)\", then I don't recommend using ZRP or any mod with that installation location, as it is for protected program and system files, not for user modification. There may be issues with UAC or Volume Shadow Copy, AKA Virtual Store.

That's what I've got to start. If I think of anything else, I'll reply again.

I followed the readme.txt provided by the ZRP mod. It says to extract and move the gamedata\ directory (from the ZRP archive) to the SoC game directory (which is not in Program Files, but a different drive altogether). So I did that and edited to fsgame.ltx file, by modifying the line:

$game_data$ = false| true | $fs_root$ | gamedata\

to

$game_data$ = true| true | $fs_root$ | gamedata\

If I understand correctly this tells SoC to use the game data files provided in that specific directory. There was no gamedata\ directory before this.

This works, because I can see the ZRP "watermarks" in the game menu after starting it.

I wonder if it has anything to do with the Good Old Games update/"refresh" GOG did recently to the game. I will try to remove the ZRP gamedata folder, replace it and start a new game.