MCP Issues with Cursor

[maxwitanowski]

Yo just been using this MCP with cursor in unity, Cursor has found some issues with the MCP, I'll show what it listed below.

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1. set_component_property Tool Fails with "Property not found" Error

The tool reports properties as not found even when they exist and are correctly named.
Example Error: Property 'cellLayout' not found. Did you mean: cellLayout?

What I Tried:

• 1. Setting Grid component's cellLayout property (enum value)
• 2. Setting Grid component's cellSize property (Vector3)
• 3. Setting TilemapRenderer component's mode and sortOrder properties
• 4. Setting custom component's asset reference fields (TileBase type)

Parameter Formats Attempted:

# Format 1: Direct values
{"cellLayout": 3, "cellSize": {"x": 1, "y": 0.5, "z": 2}}

# Format 2: Nested with "value" wrapper
{"cellLayout": {"value": 3}, "cellSize": {"value": {"x": 1, "y": 0.5, "z": 2}}}

# Format 3: Asset path for references
{"grassTile": {"assetPath": "Assets/path/to/tile.asset"}}

None of these worked. The tool always reports the property doesn't exist, even though:

• get_component shows these exact property names
• Unity Inspector shows these properties exist
• The property name in error matches exactly: "Did you mean: [same name]?"

2nd Issue:

2. Scene File Changes Don't Persist to Runtime
   Issue: Direct scene file edits via run_terminal_cmd don't reliably load into Unity runtime.
   What Happened:

3. Edited .unity scene file to change m_CellSize: {x: 1, y: 0.5, z: 1} to z: 2

4. Called execute_menu_item with "Assets/Refresh"

5. Unity Inspector showed the updated value

6. Entered Play mode

7. get_component showed runtime value was still z: 1 (old value)

Workaround: Multiple stop/start cycles and re-editing the scene file sometimes worked, but inconsistent.

3rd Issue:

Issue: After several asset refreshes and component queries, the MCP bridge stops responding.

Error: Python error managing editor: Timeout receiving Unity response

Context: Occurred after ~20-30 minutes of repeated:

• get_component calls
• execute_menu_item "Assets/Refresh"
• Scene file edits via terminal
• Play mode start/stop cycles

Recovery: Required Unity restart (or waiting indefinitely).

These issues make automated Unity configuration via MCP extremely difficult. Basic operations like changing Grid settings or assigning asset references require manual user intervention, defeating the purpose of the MCP integration.
Unity Version: 6000.2.8f1
MCP Package: com.coplaydev.unity-mcp (version unknown - latest from package manager)

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Has anyone else experienced these issues? Are there any work-arounds or fixes coming up? I wasn't using this MCP as a tool to let the ai run free, I have been using it along-side my own manual intervention, just an annoying blocker that meant I had to do more manual work.