Resolution of AADSTS500014: The service principal for resource https://dev.teams.microsoft.com is disabled issue

I hope Resolution of AADSTS500014: The service principal for resource https://dev.teams.microsoft.com is disabled issue is the worst post title ever which I’m publishing 😋 Yet, when I faced this error I did not find direct resolution to it…

Issue description

That might be a surprise, but I needed to work with Developer Portal and App studio in Teams:

And I was asked for the consent to use the App but Developer Portal throw error:

I started to look what could be the source of the issue and of course google for the answer. I went via various pages about similar issues with other resources blocked, but not dev.teams.microsoft.com… With that in my mind now I would like to share what worked for me to resolve this issue.

Resolution

First thing it was to navigate from https://portal.azure.com to Azure Active Directory.

Next I selected Enterprise applications:

In the Enterprise applications, note that the Application type is selected:

Unselect the Application type. After removal of the Application type filter, you will see much more Apps:

Search for App Studio:

After clicking the link of the App Studio for Microsoft Teams I opened properties:

As you see on the screenshot, the Enabled for users to sign-in? Was set to NO…

I change it to Yes and clicked Save:

NOTE:
If I’m not mistaking things this will affect all Users in your tenant.

After at moment, I saw confirmation of the action:

When I navigated back Teams and the App Studio in Developer portal started to work 🤩

I hope it will be useful and save some time of investigation.