Space Engineers 2 (1133870)

[Sveske-Juice]

Compatibility Report

• Name of the game with compatibility issues: Space Engineers 2
• Steam AppID of the game: 1133870

System Information

• OS: NixOS 25.11 (Xantusia) x86_64
• GPU: RX 6900XT
• Kernel version: 6.14.6-zen1
• Proton version: experimental-10.0-20250612c
• Steam Linux Runtime: sniper: 3.0.20250408.124536 sniper 3.0.20250408.124536

I confirm:

• [x] that I haven't found an existing compatibility report for this game.
• [x] that I have checked whether there are updates for my system available.

Proton Log

The relevant line for the problem is this line:

:warn:seh:OutputDebugStringA "Error: the required library hostfxr.dll could not be found in [Z:\\nix\\store\\pyp6xpcc67g40rwlz4sgi18qbkjyyi6h-dotnet-sdk-wrapped-9.0.105\\share\\dotnet\\host\\fxr\\9.0.4]"

Symptoms

Fails to launch with window saying: "You must install .NET Dekstop Runtime to run this application"

So it seems that having dotnet installed on host os (NixOS) (or DOTNET_ROOT env variable) makes wine look for the dll on the native host, while it should be looking for the dll in the wine prefix, right?

Workaround

Uninstall dotnet on host, and it works normally

Reproduction

This is the relevant part of my nix config which handles dotnet:

environment.systemPackages = [
  pkgs.dotnetCorePackages.dotnet_9.sdk # required for omnisharp lsp
];

# https://nixos.wiki/wiki/DotNET
environment.sessionVariables = {
  DOTNET_ROOT = "${pkgs.dotnetCorePackages.dotnet_9.sdk}/share/dotnet";
};

[kisak-valve]

Related: #8067

[Sveske-Juice]

Related: #8067

Yes, DOTNET_ROOT is definitely the issue.

Setting these launch options works around the problem: DOTNET_ROOT="" %command%

[Red007Master]

What is interesting - I can't reproduce it, I just started SE2 with DOTNET_ROOT=/usr/bin/dotnet ... %command% but it still works perfectly fine.

Maybe it's some layered problem? Can't somebody who DON'T have this problem reproduce it?

But yea, anyway setting DOTNET_ROOT as global sounds like terrible idea, just set it separably for apps that need it.

[kisak-valve]

[Space Engineers 2] Persistent launch crash due to Fsync/RT priority conflict on Arch Linux/NVIDIA

Issue transferred from https://github.com/ValveSoftware/Proton/issues/9276. @C10udN9n3 posted on 2025-12-03T04:11:10:

Compatibility Report

• Game: Space Engineers 2
• Steam App ID: 1133870

System Information

• GPU: RTX 4090
• Video driver version: Nvidia 580.105.08
• Kernel version: 6.17.9-zen1-1-zen
• Link to full system information report as Gist: https://gist.github.com/C10udN9n3/a00e8b951349544ec7d42dc1f486f236
• Proton version: Attempted all: Proton-GE 10-25, Proton 9.0-2, Proton 9.0-4, Proton 10-03

I confirm:

• [ X] that I haven't found an existing compatibility report for this game.
• [ X]that I have checked whether there are updates for my system available.

Note: Crashes happen before Proton can really start, no logs can be found. Proton Did not start up for logs to be saved.

Symptoms

Immediate crash.

Reproduction

Pressing start on the game. This can be reproduced after tweaking and configuring wine and proton, on all mentioned proton versions, including a custom Proton-GE 10-25