LangSmith MCP Connection Issue

### MCP server URL or name

https://api.smith.langchain.com/mcp

### How are you connecting to this server?

From a custom connector URL I entered manually

### Where does the issue occur?

When pressing the Connect button

### When did you last reproduce this?

2026-07-28 8:52pm ET

### Browser and OS

Claude Desktop and Claude.ai (MS Edge on Windows)

### Describe the issue

Previously working MCP was erroring (with the same error message as below) for other users on Enterprise account. Disconnected and removed MCP per instructions. Now I'm getting the same error.

### Error details

```shell
Couldn’t register with LangSmith MCP’s sign-in service. You can try again, or add an OAuth Client ID in the connector settings. If this persists, share this reference with support: “ofid_b8e5323d5d83114e”
```

### Expected behavior

LangSmith MCP should connect and be available to others in our org. It OAuths to our LangSmith account.

### Additional context

The MCP and auth work fine in Claude Code. Only Claude.ai is having this issue.