Fix DLL Errors in Unity Games (Mono, IL2CPP)

Unity games may show these errors:

Mono Runtime (Older Unity Games): - mono.dll is missing - mono-2.0-bdwgc.dll not found

IL2CPP Runtime (Newer Unity Games): - GameAssembly.dll error - UnityPlayer.dll is missing

Visual C++ Runtime: - VCRUNTIME140.dll missing - MSVCP140.dll not found

DirectX: - D3D11.dll errors - D3DCompiler errors

Unity game DLLs should come with the game:

Steam: 1. Right-click game → Properties 2. Local Files → Verify integrity of game files

Epic Games: 1. Click three dots on game 2. Verify

GOG Galaxy: 1. Click game → Manage 2. Verify / Repair

This restores mono.dll, UnityPlayer.dll, and other game files.

Unity games require Visual C++ Runtime:

Download and install: - VC++ 2015-2022 x64 - VC++ 2015-2022 x86

For older Unity games (pre-2019): - VC++ 2013 - VC++ 2012

Restart computer after installation.

For D3D and DirectX errors:

Step 1: Download DirectX End-User Runtime

Step 2: Run the installer

Step 3: Restart computer

Step 4: Check game folder for DirectX installer: `` [Game Folder]\_CommonRedist\DirectX\ `` Run if present.

If DLLs are corrupted beyond repair:

Step 1: Note any save game locations (check PCGamingWiki.com)

Step 2: Uninstall the game

Step 3: Delete remaining game folder

Step 4: Reinstall the game

Step 5: Before launching: - Right-click game in library - Check for runtime installers in game properties - Run any prerequisite installers

For GameAssembly.dll errors (IL2CPP games): - May be antivirus quarantine - check AV logs - Add game folder to antivirus exclusions - Restore quarantined files

For mono.dll errors: - Check game folder for Mono folder - If missing, verify game files or reinstall

For modded games: - Remove all mods - Verify game files - Test vanilla game first - Re-add mods one at a time

Common Unity games with DLL issues: - Subnautica - Hollow Knight - Cuphead - Risk of Rain 2 - Valheim