Troubleshooting

Troubleshooting

Common issues and solutions.

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Connection Issues

"Connection refused" / Can't connect to Unreal

Check these:

1. Is Unreal Editor running?
2. Is MCP Automation Bridge plugin enabled? (Edit → Plugins → search "MCP")
3. Is port 8091 blocked by firewall?
4. Is UE_PROJECT_PATH set correctly?

Plugin failed to load on first open

Solution: Close and reopen your project. This is normal UE behavior.

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Config Issues

Where is my MCP config file?

AI Client	Location
Claude Desktop (Windows)	%APPDATA%/Claude/claude_desktop_config.json
Claude Desktop (Mac)	~/Library/Application Support/Claude/claude_desktop_config.json
Cursor	~/.cursor/mcp.json
Windsurf	~/.config/windsurf/mcp.json

UE_PROJECT_PATH not set

Add it to your MCP config:

{
  "mcpServers": {
    "unreal-engine": {
      "command": "npx",
      "args": ["unreal-engine-mcp-server"],
      "env": {
        "UE_PROJECT_PATH": "C:/Path/To/YourProject"
      }
    }
  }
}

Port already in use

Change the port:

"MCP_AUTOMATION_PORT": "8092"

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Plugin Issues

Plugin not showing in Editor

1. Verify plugin is in YourProject/Plugins/McpAutomationBridge/
2. Delete Intermediate folder
3. Regenerate project files
4. Restart Unreal Editor

Build errors (out of memory)

The plugin uses NoPCHs to prevent memory issues. If still failing:

1. Close other applications
2. Increase Windows page file
3. Build in Release configuration

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Tool Issues

"Tool not found"

1. Check spelling (use exact tool names from Tools Reference)
2. Update: npx unreal-engine-mcp-server@latest

"Action not supported"

1. Verify the action exists for that tool
2. Ensure required plugin is enabled

Tool not working (Sequencer, Animation, GAS, etc.)

Some tools need additional plugins:

Tool	Enable This Plugin
manage_sequence	Level Sequence Editor
animation_physics	Control Rig
manage_geometry	GeometryScripting
manage_behavior_tree	Behavior Tree Editor
manage_gas	Gameplay Abilities

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Performance Issues

Slow responses

Increase timeout:

"MCP_AUTOMATION_REQUEST_TIMEOUT_MS": "300000"

Asset not found

1. Use /Game/ prefix (not /Content/)
2. Verify asset exists in Content Browser
3. Check path format: /Game/Folder/AssetName

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Debug Mode

Enable debug logging to troubleshoot:

"LOG_LEVEL": "debug"

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Still Stuck?

Resource	Link
GitHub Issues	https://github.com/ChiR24/Unreal_mcp/issues
Discussions	https://github.com/ChiR24/Unreal_mcp/discussions

When reporting issues, include:

• Unreal Engine version
• MCP Server version
• Error message
• Steps to reproduce