Power Platform Community Forum Thread Details

Error in MCP custom connector

Hi ,

I wanted to know what exactly can be causing this error on the custom power connector for MCP in my copilot topic. The agent works as expected while using in copilot studio. This is the error i get when publishing.

    "diagnosticResult": [
      {
        "$kind": "ElementValidationError",
        "errorCode": "ExternalAgentTaskActionDoesNotAllowRedirect",
        "errorMessage": "Element is invalid: ExternalAgentTaskActionDoesNotAllowRedirect"
      }

For more context, my MCP server is hosted as a web app which my azure APIM makes a request to. My power connector is only for the azure APIM url.

This error has started appearing after the May 29th MCP general availability update. What i've tried so far is:

removed custom connector from copilot studio and re add them.
Created a new custom connector in power platform, add that to a new topic in agent.
simply remove action from a topic and add it back again.

I'm not sure where the redirect is coming from .

My custom power connector swagger.

swagger: '2.0'
info:
  title: CatalystMCPRUNN
  description: MCP server for catalysts.
  version: 1.0.0
host: my-custom-mcp.azure-api.net
basePath: /
schemes:
  - https
definitions:
  QueryResponse:
    type: object
    properties:
      jsonrpc:
        type: string
      id:
        type: string
      method:
        type: string
      params:
        type: object
      result:
        type: object
      error:
        type: object
paths:
  /runn/sse:
    get:
      summary: MCP Server Actions
      parameters:
        - in: query
          name: sessionId
          type: string
          required: false
      produces:
        - application/json
      responses:
        '200':
          description: Immediate Response
          schema:
            $ref: '#/definitions/QueryResponse'
        '201':
          description: Created and will follow callback
      operationId: InvokeMCP
      tags:
        - Agentic
        - McpSse
securityDefinitions: {}
security: []