Cursor Broken After Cocos Creator MCP: Fix Connection by Symptom

After you install Cocos MCP and configure it once in Cursor, many people feel Cursor is broken: the chat cannot touch the scene, the MCP panel is all red, or it worked yesterday and vanished today. In most cases Cursor itself is fine—the MCP bridge is down. Either the Creator-side server is not running, or Cursor’s config / reload never took effect.

This guide starts from symptoms you can see in Cursor, so you know which layer to check next. Long Creator steps (extension import, activation codes, port conflicts) live in the general guide: Cocos MCP connection troubleshooting. If you still need the product boundary, see What Is Cocos Creator MCP.

First: Is Cursor Broken, or the Bridge?

What you feel	More likely cause
Cursor still writes normal code, but cannot reach Cocos scenes/nodes	MCP not connected or tools not enabled
MCP list has no cocos-creator (or the name from Quick configure)	Config not written, or Reload needed
Service name exists but shows error / disconnected	Creator not Running, wrong URL/port, or reload needed
Shows connected, but cannot list nodes of the open scene	Wrong project, tools unchecked, or bad read-only check

Claude Code, Codex, and similar MCP clients follow the same idea: confirm the client has a healthy service entry, then check Creator.

Step 1: Look Only at MCP Inside Cursor

Open Cursor’s MCP / tools settings (menu labels may vary by version) and check:

1. Whether cocos-creator appears (or the name written by Creator’s Quick configure)
2. Whether status is connected / usable—not stuck in error, disconnected, or blank
3. If you just changed config or ran Auto configure in Creator: do a Reload Window (or equivalent MCP reload), then recheck the list

A common case: Creator already shows Running, but Cursor still holds a stale config—without reload it feels “suddenly broken.”

Step 2: Confirm the URL Points at Local Creator

The Cursor MCP entry should target a local bridge URL, usually:

• http://127.0.0.1:3000/mcp
• or http://localhost:3000/mcp

Use the port shown in Creator’s MCP panel (often 3000 by default; if you changed it, match the panel).

Also open Cocos Creator and confirm the MCP panel is Running for the same project. If the panel is not running, Reload in Cursor will not magically expose tools.

Product pages (pick the package for your major version; do not mix):

• Cocos MCP 3.x
• Cocos MCP 2.x

Step 3: If It Still Fails, Jump by Layer

The MCP path has four layers. Failure at any layer can look like “Cursor is broken / won’t connect”:

1. Plugin in the project and enabled
        ↓
2. Panel activated (account / license code)
        ↓
3. MCP Server shows Running (localhost)
        ↓
4. Cursor has config written and MCP list shows connected

What you see in Cursor	Go here first
No service entry at all	Layer 4: back to Creator → Quick configure → Auto configure, then Reload; details in the general guide
Entry exists but error / cannot connect	Layer 3: is Creator Running, does the port match, is localhost blocked
No MCP menu inside Creator	Layer 1: 2.x/3.x package mix-up, import path, restart (general guide symptom A)
Panel cannot start / not activated	Layer 2: account and activation (general guide)
Connected but cannot list nodes	Confirm the right project is open; run the read-only smoke below; then check tool toggles

Full install:

• Cocos Creator 3.x MCP install
• Cocos Creator 2.x MCP install

Step 4: Smoke Test (Confirm It’s Fixed)

In Cursor, start with a read-only check, for example:

List the root nodes of the scene currently open in Cocos Creator.

If the reply matches the editor hierarchy, the bridge works. Optionally do one reversible write (create a temp node and delete it). Commit before large edits; keep the bridge on localhost only—do not expose the MCP port to the public internet.

FAQ

What does “Cursor broken” after Cocos Creator MCP usually mean?
Typical signs: no MCP service entry, red/error status, or connected with no tools/nodes. Most cases are not a Cursor crash—they are one missing layer in the four-layer bridge.

Should I check Cursor or Creator first?
Start with Cursor’s MCP list (missing vs red). Then verify Creator: plugin imported/enabled, panel activated, server Running, port matches config. Use the symptom table in this article.

Connected but no nodes—what next?
Confirm the right project/scene is open; run a read-only smoke test (list root nodes). If it still fails, check tool toggles and permissions. Full path: connection troubleshooting.

Do I need to reinstall Cursor?
Usually no. Prefer Creator “quick configure → auto configure,” reload MCP, and verify the localhost port. Category boundary: What Is Cocos Creator MCP.