Re-adding MCP server results in "A server with this URL already exists"

[armandn]

What happened?

I created a custom MCP server. Worked. Next day, I made some changes and had to remove it via Claude Desktop. It's gone from the UI and .claude.json. But if I want to add it, I get 2 errors in Claude Desktop:

• A server with this URL already exists
• Failed to add connector

What did you expect to happen?

I should be able to add a previously-removed connector / MCP server

Steps to reproduce

1. Add connector
2. Remove
3. Add again

Area

MCP Connector (adding/managing servers)

MCP Server (if applicable)

customer staging server

Error messages or logs

Additional context

No response

[localden]

Thanks for the report. To narrow this down:

1. Is this connector also showing under claude.ai web at https://claude.ai/settings/connectors when you sign in with the same account? Custom connectors added through Desktop's settings are stored on your account, not just locally, so removing the local entry may not have removed the account-level one.
2. What is the exact server URL you are entering when re-adding?
3. Did the original connector have a manually configured OAuth client ID and secret in its advanced settings?

If you see it listed on claude.ai web, removing it there and then re-adding should work.

[armandn]

Yes, it occurred to me to try - I checked https://claude.ai/settings/connectors and it was there and I was able to remove it. Afterwards I was able to re-add it. So the bug was that removing a connector locally via Claude Desktop may not remove the account-level setting.
In case it helps, the connector didn't have any manual settings, it was fully OAuth.

[superayan]

+1

[CagriKIRT]

+1 i get this when i try to add my self host n8n mcp server.