Share via

Adding MCP Server as Tool in Copilot Studio fails with strange error msg

Stefan Solender 15 Reputation points
2026-04-17T11:57:05.4266667+00:00

I have created a custom MCP Server in Azure (python container app) and want to add it as a tool for my agent. Under "tools" tab in Copilot Studio I chose to add a new Model Context Protocol Server, and always get (last three days or so) even with very different names:
"Something went wrong. Please try again.A custom connector with display name 'MCP Server for Snowflake' already exists in the environment. It may have been created by another user or may not be visible to you. Please specify a different name."

Its my first MCP Server.
User's image

Microsoft Copilot | Other
0 comments

5 answers

Sort by: Most helpful
Most helpful Newest Oldest
  1. Stefan Solender 15 Reputation points
    2026-04-17T13:34:59.84+00:00

    I added the schema endpoint (/.well-known/mcp/schema) and it is ANONYMOUS and return 200 and a valid JSON. Then tried to add it again with yet another (new and unique) name. Same error. Looked in Power Platform admin center, but can not see any connectors. I think it is VERY unlikely we have a name collision every time. The error message is misleading.

    Was this answer helpful?

    1 person found this answer helpful.
  2. Jared Roberts 0 Reputation points
    2026-04-21T05:22:27.6733333+00:00

    This happens to me when I try and connect to SAP LeanIX. There is no Custom Connector view to check. This is very frustrating as the error is clearly misleading and there is nowhere to troubleshoot. I managed to create it in another environment, but I have no idea how I will fix the issue in the Environment that I wanted to create the connection.

    Was this answer helpful?

    0 comments
  3. dklaassen 0 Reputation points
    2026-04-18T22:39:58.8933333+00:00

    Hi there,

     

    I am having the same issue trying to setup HaloPSA MCP Connection (https://usehalo.com/halopsa/guides/2711/) Please let me know when you find a solution.

    Was this answer helpful?

    0 comments
  4. Sayali-MSFT 5,766 Reputation points Microsoft External Staff Moderator
    2026-04-17T12:51:49.27+00:00

    Hello Stefan Solender ,
    When adding a custom MCP Server in Copilot Studio, the platform automatically creates a Power Platform Custom Connector in the background using the Server Name provided. If MCP onboarding fails at any stage—such as schema validation timeout, authentication challenge on the schema endpoint, or improper MCP metadata response—the connector may still get partially created in Dataverse but won’t appear in the Copilot Studio UI. This results in subsequent attempts to add the MCP failing with the misleading error stating that a connector with the same display name already exists in the environment, even when different names are used. The root cause is typically these hidden or orphaned custom connectors created during failed MCP onboarding.
    To resolve this, navigate to the same environment in Power Apps (make.powerapps.com), manually delete any related connectors under Custom Connectors, wait a few minutes for metadata sync, and retry MCP creation using a unique name. Additionally, ensure that your MCP container exposes a publicly accessible /.well-known/mcp/schema endpoint that returns a valid JSON response with HTTP 200 and does not require authentication, as Copilot Studio performs a schema probe during MCP registration.

    Was this answer helpful?

  5. Q&A Assist
    2026-04-17T11:57:25.9266667+00:00
    AI generated content. This question contains an answer created with AI from Q&A Assist. Learn more

    The error indicates that Copilot Studio is trying to create a Power Platform custom connector behind the scenes for the MCP server, and a connector with that display name already exists in the current environment (possibly created earlier or by another user). The MCP onboarding wizard requires a unique connector name per environment.

    To proceed, use one of these approaches:

    1. In the same Copilot Studio environment, choose a completely new, unique Server name when running the MCP onboarding wizard. This forces creation of a new underlying custom connector.
    2. If there is access to Power Apps/Power Platform admin tools, locate and remove or rename the existing custom connector that has the conflicting display name, then rerun the wizard with the desired name.
    3. If tenant policies or hidden connectors are causing conflicts (for example, created by another user and not visible), create or switch to a different Copilot Studio/Power Platform environment and add the MCP server there using the MCP onboarding wizard.

    Once the MCP server is successfully added as a tool, it appears on the agent’s Tools tab and can be configured and used like other MCP connectors.

    References:

    Was this answer helpful?

Your answer

Answers can be marked as 'Accepted' by the question author and 'Recommended' by moderators, which helps users know the answer solved the author's problem.