Custom Connector - Unauthorized (401) - Power BI

[buildbod]

I have followed a post from the Microsoft Power BI community for creating a custom connector for Power BI in Flow.

All was fine until I tested the connector in the final screen of the custom connector setup in Flow. The operation would fail with a (401) unauthorized.

401 response when testing the connector

The error is:

{
  "strict-transport-security": "max-age=31536000; includeSubDomains",
  "x-content-type-options": "nosniff",
  "date": "Fri, 17 May 2019 12:07:54 GMT",
  "requestid": "47ede081-3570-486c-a1ae-149ee435c273",
  "x-frame-options": "deny",
  "content-type": "application/octet-stream",
  "cache-control": "no-store, must-revalidate, no-cache",
  "transfer-encoding": "chunked"
}

I double checked my connection in Flow and it has a status of Connected.

Flow connection - valid connection

The only differences between my connector and the post are:

[1] I am testing it with a call to the Datasets - Get Refresh History In Group end point. I know this works as I have validated it using the Try It feature in documentation. I have set the App in AD with the correct scopes.

[2] The automatically generated Redirect URL. The app automatically created a Redirect URL of https://global.consent.azure-apim.net/redirect yet the requests are going to https://europe-001.azure-apim.net/redirect. I added the europe address to the Redirect URIs for the app in Azure AD but I cannot change it in the custom connector. Adding the europe address in Azure AD made no difference.

Automatically generated and uneditable Redirect URL

Request header calling europe

Europe and global redirects in AD

This has left me puzzled as to what has gone wrong. I have deleted and recreated the connector and that made no difference. For completeness below are each screen for the connector.

General configurationSecurity configurationDefinition configuration - GeneralDefinition configuration - RequestDefinition configuration - ValidationTest configuration

[Brad_Groux]

First, thank you so much for providing a detailed overview of your issue. It greatly helps those trying to support you!

With that said, insure that your PowerApp resides in a PowerApps Environment that has access to the Flow (so in the same Office 365 tenant). You select your PowerApps environment from the top bar of the PowerApps portal (documentation), example: 

I've made this mistake many, many times. I was using an environment that didn't have access to the same Flow tenant. Also, you may want to verify that each step of your Flow is using the right credentials under the My connections popup, example:

If you still have 401 errors, you should reach out to your Office 365 administrators, and have them verify your environment permissions (documentation). 

If this reply has answered your question or solved your issue, please mark this question as answered. Answered questions helps users in the future who may have the same issue or question quickly find a resolution via search. If you liked my response, please consider giving it a thumbs up. THANKS!

[buildbod]

Thanks @Brad_Groux  . I've double checked the environments and it is not that.

[buildbod]

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I've also tried limiting the reply uri's suggested by this post in the Power BI community. 

[buildbod]

Cross posted in the Power BI community https://community.powerbi.com/t5/Service/Custom-Connector-from-Flow-to-Power-BI-Unauthorized-401/m-p... 

[Brad_Groux]

You may want to submit a support request to the Flow team. Unfortunately, for authorization errors we can't really be of assistance. There is obviously a permissions error someplace in your account and/or environment. 

To submit a support request visit https://flow.microsoft.com/support/ and click the Contact Support link in the bottom right hand corner of the page:

If this reply has answered your question or solved your issue, please mark this question as answered. Answered questions helps users in the future who may have the same issue or question quickly find a resolution via search. If you liked my response, please consider giving it a thumbs up. THANKS!

[buildbod · Accepted solution]

Problem solved after a support call with Microsoft. It appears that behind the scenes the Custom Connector may not establish correctly the first time of creation. Create a second connector and it works fine. Then remove the first one.