Unity pings to http server infinitely.. #441
Description
🌐 Unity Error Analysis: Main Thread Access Violation
1. 🔍 Error Message Detailed Analysis
The core of the issue is a violation of Unity's threading model, where a function that requires synchronization is being called from a background thread.
Log Section | Meaning -- | -- [WebSocket] Unexpected receive error: HasKey can only be called from the main thread. | This is the direct cause of the error. The background thread handling WebSocket communication is attempting to call HasKey() (likely PlayerPrefs.HasKey()), which is a function that must be executed on the Main Thread only. HasKey | This typically refers to a function accessing resources that require thread safety, such as PlayerPrefs (which accesses the file system). Unity requires synchronization for these APIs. MCPForUnity... WebSocketTransportClient/d__36:MoveNext () | The problem originates within the WebSocket communication logic of the MCP-FOR-UNITY package. It confirms that the HasKey call is embedded within the asynchronous receive loop.2. 💡 Root Cause: Unity API Access from a Background Thread
Unity handles all visual updates, physics, and core API calls on a single Main Thread. Network operations, like WebSocket transport, run on separate asynchronous threads for performance. When a background thread attempts to call a critical Unity API (like accessing PlayerPrefs or potentially other synced data), it violates this threading rule, leading to the error.
3. 🛠️ Recommended Solutions (For Package Developer)
Since this error points directly to an issue within the MCPForUnity package code, the primary fix must be implemented by the developer responsible for that package.
🛠️ Action 1: Package Code Modification (Recommended)
The code at the source of the error (WebSocketTransportClient.cs:299) needs to be modified to ensure the HasKey() call is executed on the Main Thread.
Implementation: The code block containing the forbidden API call must be marshaled back to the Main Thread. In Unity Editor scripts, this is typically done using methods like:
C#UnityEditor.EditorApplication.update += () => { // Code to run on the main thread };
🛠️ Action 2: Update or Report
If direct modification is not feasible, the developer should check if the issue has been resolved in a newer version of the package (currently com.coplaydev.unity-mcp@fd44ab3b5d) or report this detailed error log to the package maintainers for an official fix.
🛠️ Action 3: Editor Restart
As a temporary measure for sporadic issues, restarting the Unity Editor may clear up any temporary threading state confusion, though this does not fix the underlying code bug.
am i only struggled with this issue?