CET 1.37.1 EXCEPTION_ACCESS_VIOLATION (c0000005) on Linux - Zorin 18 / GE-Proton10-34

[wolveythorax-pixel]

Environment:

• OS: Zorin OS 18 (Ubuntu 24.04 base)
• Steam: Native .deb install
• Proton: GE-Proton10-34 (also tested Proton Experimental, Proton 10.0-4)
• Game: Cyberpunk 2077 v2.31 with Phantom Liberty
• CET: v1.37.1

Launch options:
WINEDLLOVERRIDES="version=n,b" %command%

DLL overrides in prefix (via protontricks winecfg):
version = native,builtin
d3dcompiler_47 = native
vcrun2022 installed

Issue:
CET's version.dll loads successfully as native, and cyber_engine_tweaks.asi is found and loaded, but CET crashes during initialization with EXCEPTION_ACCESS_VIOLATION (c0000005).

Proton log (PROTON_LOG=1):

Loaded L"S:\\common\\Cyberpunk 2077\\bin\\x64\\VERSION.dll" at 00006FFFDEA10000: native
Loaded L"S:\\common\\Cyberpunk 2077\\bin\\x64\\plugins\\cyber_engine_tweaks.asi" at 00006FFFDE130000: native
code=c0000005 (EXCEPTION_ACCESS_VIOLATION) flags=0 addr=00006FFFFCDD2EB0
backtrace: 00006FFFDE15C9A7: L"cyber_engine_tweaks.asi" + 000000000002C9A7
backtrace: 00006FFFDE434509: L"cyber_engine_tweaks.asi" + 0000000000304509
backtrace: 00006FFFDE174E6F: L"cyber_engine_tweaks.asi" + 0000000000044E6F
backtrace: 00006FFFDE135758: L"cyber_engine_tweaks.asi" + 0000000000005758
backtrace: 00006FFFDE15C143: L"cyber_engine_tweaks.asi" + 000000000002C143
backtrace: 00006FFFDE15C962: L"cyber_engine_tweaks.asi" + 000000000002C962
backtrace: 00006FFFDE6948CA: L"cyber_engine_tweaks.asi" + 00000000005648CA
Unloaded module L"S:\\common\\Cyberpunk 2077\\bin\\x64\\plugins\\cyber_engine_tweaks.asi" : native

What I've tried:

• Multiple Proton versions (Experimental, 10.0-4, GE-Proton10-34)
• protontricks winecfg DLL override for version
• Installed d3dcompiler_47 and vcrun2022
• File permissions (chmod +x on .dll and .asi)
• Clean CET reinstall
• Disabled Steam overlay
• Copied msvcp140_atomic_wait.dll to bin/x64
• Migrated from Flatpak Steam to native Steam .deb

The ASI loader works correctly - it loads version.dll native and finds the .asi. The crash is inside CET's own initialization code.

[wolveythorax-pixel]

ROOT CAUSE FOUND AND FIX CONFIRMED:

The crash occurs at MSVCP140.dll + 0x12EB0, NOT in CET code. Using PROTON_LOG=1, the backtrace shows:

warn:seh:virtual_unwind backtrace: 00006FFFFCDD2EB0: L"MSVCP140.dll" + 0000000000012EB0

The MSVCP140.dll installed by protontricks vcrun2022 is version 14.28.29334.0 (VS 2019 era), but CET 1.37.1 was compiled with MSVC 19.44.35217 (VS 2022) and requires the matching C++ runtime.

Fix: Install the latest VC Redistributable directly inside the Wine prefix:

1. Download: curl -L -o vc_redist.x64.exe "https://aka.ms/vs/17/release/vc_redist.x64.exe"
2. Copy to prefix: cp vc_redist.x64.exe ~/.local/share/Steam/steamapps/compatdata/1091500/pfx/drive_c/
3. Run via protontricks: flatpak run com.github.Matoking.protontricks -c 'wine "C:\vc_redist.x64.exe" /quiet /norestart' 1091500

This updates MSVCP140.dll from 14.28 to 14.44.35211.0, matching CET's compiler. CET loads and runs correctly after this fix.

Proposed improvement for CET:

1. Bundle required MSVCP140/VCRUNTIME140 DLLs in the CET distribution
2. Or document the minimum required VC runtime version for Linux/Proton users
3. Or add a version check on load that logs a clear error about runtime version mismatch