Troubleshooting · 8 min read · Updated October 18, 2026

Roblox Studio MCP not connecting? 12 fixes

Almost every "the AI can't see my game" problem is one of a handful of setup issues, and most of them take under a minute to fix. This page goes in the order that solves the most cases. Fixes 1 to 9 are for ForgeBlox (formerly Forge) and its Bridge; fixes 10 to 12 are for anyone connecting Claude Code, Cursor or another MCP client to Studio directly. Studio steps follow Roblox's own MCP documentation.

First, read the signal

Studio's MCP server only listens on your own PC. Something on that PC has to start it and talk to it: for ForgeBlox that is the Bridge window; for other clients it is the client itself. Each one tells you which link is broken.

1. Turn on Studio's MCP server (the most common fix)

1. Open a place in Roblox Studio. The start page is not enough; New ▸ Baseplate is fine.
2. Click Assistant in the top bar.
3. Click the ⋯ menu at the top right of the Assistant panel and choose Manage MCP Servers.
4. Turn on Enable Studio as MCP server.

A green indicator under the switch shows how many clients are connected. With ForgeBlox, the Bridge window prints "✔ Studio connected" with your place name within about ten seconds, and the sidebar turns green. If you have just updated Studio, check the switch again.

2. Open an actual place, on the same PC

If the Bridge says "Roblox Studio is not open on this PC", it means exactly that: it looked for the Studio process and did not find it. Open Studio on the PC where the Bridge is running and open a place. The Bridge and Studio must be on the same Windows PC, because Studio's MCP server never accepts connections from other machines.

3. "Could not find Roblox Studio on this PC (StudioMCP.exe)"

Roblox installs a small program called StudioMCP.exe with Studio. The Bridge finds it through Studio's install location and the version folders under %LOCALAPPDATA%\Roblox\Versions. If it is not there:

• Install or update Roblox Studio from the Roblox website, then open Studio once so it finishes installing.
• Restart the Bridge.
• If you installed Studio for a different Windows user, run the Bridge as that user.

4. The Bridge is not running

The Bridge adds itself to Windows startup when you first pair, but if you closed its window it is not running now. Double-click forge-bridge.exe again (or download it) and leave the window open, minimised. It reconnects on its own if your internet blips.

5. A firewall, antivirus or school network is blocking it

If the Bridge window says "Still cannot reach Forge", it also prints the likely reason:

• "The connection is being blocked." Allow forge-bridge.exe through Windows Defender Firewall and your antivirus. To confirm it is the network, try a phone hotspot for a minute.
• "Something on this network is intercepting HTTPS." School and work networks and some antivirus web filters do this. Try another network or add an exception for forgeblox.app.
• "This PC cannot resolve forgeblox.app." A DNS or internet problem. Check that the PC is online and that a browser can open forgeblox.app.

6. Two copies of the Bridge are fighting

If the window says "Replaced by another bridge", a second copy is running with the same pairing, often one from Windows startup plus one you double-clicked. Close every Bridge window (check the taskbar and Task Manager), then start one.

7. The pairing was removed

If you unpaired PCs from the ForgeBlox sidebar, or pairing was reset, the Bridge says "This PC's pairing was removed or is no longer valid" and shows a new six-letter code. Type it in ForgeBlox ▸ sidebar ▸ Bridge. You do not need to download anything again.

8. Several Studio windows are open

Studio's MCP server can see more than one Studio window, and Roblox's tools take a Studio id to choose between them. ForgeBlox lists the places it can see in the sidebar. If the wrong place is listed or edits land in the wrong place, close the Studio windows you are not building in.

9. It disconnected in the middle of a build

If you see "Lost the connection to Forge Bridge", the Bridge on your PC went away during a build, usually because Studio or the Bridge was closed, the PC slept, or the network dropped. Your project and everything built so far are saved and you pay only for the work done. Make sure both are open and green, then send continue.

When the Bridge or Studio is not connected at the moment you send a message, ForgeBlox stops before doing anything and you are not charged.

10. Claude Code, Cursor or another client: restart both

Roblox's first troubleshooting step is to restart both Roblox Studio and your MCP client. Many clients only read their MCP list at startup, and Studio's Quick connect list only shows clients that were installed before Studio started. If your client is missing from Assistant Settings ▸ MCP Servers ▸ Quick connect, install it, then restart Studio.

11. Check the command path

Roblox documents these commands for clients you configure by hand:

Paste %LOCALAPPDATA%\Roblox into File Explorer's address bar to check that mcp.bat exists. If it does not, update Studio and open it once. In Claude Code, claude mcp list shows each server's status and /mcp shows it inside a session. Our Claude with Roblox Studio guide has the full setup.

12. Check the JSON

For clients configured with a JSON file, a missing comma or bracket stops the whole file from loading. The entry should look like this on Windows (note the doubled backslashes inside JSON strings):

{
  "mcpServers": {
    "Roblox_Studio": {
      "command": "cmd.exe",
      "args": ["/c", "%LOCALAPPDATA%\\Roblox\\mcp.bat"]
    }
  }
}

If you already have other servers, add Roblox_Studio inside the same mcpServers object, separated by a comma.

Still stuck?

The ForgeBlox Bridge sends a short diagnostic to our support team when it cannot connect (no Roblox data or place content: the error, the Bridge and Windows versions, and the PC's name), so we can usually tell what happened. Ask in the Discord or email support@forgeblox.app with a screenshot of the Bridge window.

Questions

Sources

• Roblox, Connect to the Roblox Studio MCP server, checked October 18, 2026 (enable steps, Quick connect, commands, troubleshooting, multiple Studio instances).
• Anthropic, Claude Code MCP documentation, checked October 18, 2026 (claude mcp list, /mcp).
• ForgeBlox Bridge messages as shipped in October 2026.

Related guides

• Roblox Studio's MCP server, explained
• How to use Claude with Roblox Studio
• Download the ForgeBlox Bridge