Mount & Blade II: Bannerlord (261550)

Compatibility Report

• Name of the game with compatibility issues: Mount & Blade II Bannerlord
• Steam AppID of the game: 261550

System Information

• GPU: X.Org AMD Radeon RX 5700 XT (NAVI10, DRM 3.36.0, 5.5.11-050511-generic, LLVM 9.0.0)
• Driver/LLVM version: 4.5 (Compatibility Profile) Mesa 19.2.8
• Kernel version: 5.5.11-050511-gen
• Link to full system information report as Gist: https://gist.github.com/Yarwin/5648be675565aafa1e3930fede59ca07
• Proton version: 5.0-5

I confirm:

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

Proton crash log:

steam-261550.log

Symptoms

Game don't launch

Reproduction

1. Download M&B II: Bannerlord
2. Try to run it
3. Game crashes with:

Unhandled Exception:
System.IO.FileNotFoundException: Could not load file or assembly 'ManagedStarter, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null' or one of its dependencies.
File name: 'ManagedStarter, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null'

message in the log.

Current workaround

Proton 5.5-GE https://github.com/GloriousEggroll/proton-ge-custom/releases/tag/5.5-GE-1 + protontricks 261550 dotnet472 (Bannerlord necessary dependencies can be found there: https://forums.taleworlds.com/index.php?threads/installing-missing-necessary-dependencies.407126/)
Installing dotnet core might significantly reduce number of crashes: https://github.com/ValveSoftware/Proton/issues/3706#issuecomment-609959973, https://github.com/ValveSoftware/Proton/issues/3706#issuecomment-610022040

Multiplayer: it works, just skip installation of a BattleEye when prompted.

Start with the attached steam-261550.log and the reproduction steps for Mount & Blade II: Bannerlord under Proton 5.0-5. Compare them with the reported Proton 5.5-GE and protontricks dotnet472 workaround, including the linked dependency information. Done means identifying and resolving the launch failure without relying on that workaround.