UnrealMCP compiled for UE 5.6 - Windows x64

[lagisela]

I successfully compiled UnrealMCP for Unreal Engine 5.6!

Build Info

• Unreal Engine: 5.6
• Platform: Windows x64
• Visual Studio: 2022

Fixed Issues

• Renamed global BufferSize variable to fix compilation error
• Removed comment from .uplugin JSON file

Download

[See attached ZIP file below]

This should help others who need UnrealMCP for UE 5.6!

UnrealMCP_UE5.6_WinX64.zip

[lagisela]

UnrealMCP compiled for Unreal Engine 5.6 - Windows x64

I successfully compiled UnrealMCP for Unreal Engine 5.6! Since the original plugin only supports up to UE 5.4, this might help others who need it for 5.6.

Build Environment

• Unreal Engine: 5.6
• Platform: Windows x64
• Visual Studio: 2022 (MSVC 14.38.33130)
• Windows SDK: 10.0.22621.0

Required Fixes

1. C++ Compilation Error

• Issue: Name collision with global BufferSize variable
• Error: error C4459: declaration of 'BufferSize' hides global declaration
• Fix: Renamed global constant in MCPServerRunnable.cpp from BufferSize to MCPBufferSize

2. Plugin JSON Syntax

• Issue: Invalid JSON in UnrealMCP.uplugin (comment with //)
• Error: JsonReaderException: '/' is invalid after a value
• Fix: Removed the comment - JSON doesn't support comments

3. Missing Dependency

• Issue: Module uses EditorScriptingUtilities but doesn't declare it
• Warning: Plugin 'UnrealMCP' does not list plugin 'EditorScriptingUtilities' as a dependency
• Fix: Added to UnrealMCP.uplugin:

"Plugins": [
  { "Name": "EditorScriptingUtilities", "Enabled": true }
]

[jonathanhawkins]

I opened PR #33 that formalizes the UE 5.6 build fix: replace global BufferSize with an internal named constexpr, allocate +1 byte for null-termination, and cap Recv to the constexpr size. Also updated the sample .uproject EngineAssociation so it opens in UE 5.6.\n\nIf you have a chance, please try that branch and confirm it works for you too.\n\nPR: https://github.com/chongdashu/unreal-mcp/pull/33\nDocs: EngineAssociation https://dev.epicgames.com/documentation/en-us/unreal-engine/API/Runtime/Projects/FProjectDescriptor/EngineAssociation