"Uploading custom apps is not allowed" When Installing Microsoft Teams Sample App

[Clippy]

“Uploading custom apps is not allowed” When Installing Microsoft Teams Sample App

[ayi]

I had the same problem and it actually made me crazy especially because it may take a few hours to apply changes. Finally I was able to resolve the problem in the following way. I can imagine that certain steps are unnecessary but who knows.

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  By following instructions in the Manage app setup policies in Microsoft Teams, enable “Upload custom apps” in “Global (Org-wide default)”.

  
  


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  Following same instructions created a custom setup policy with enabled “Upload custom apps”.

  
  


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  Enable all permissions in “Global (Org-wide default)” as described in the Manage app permission policies in Microsoft Teams

  
  


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  Create a new permission policy with everything enabled.

  
  


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  Wait about an hour.

  
  


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  Assign these new policies to the user.

  
  


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  Make sure that everything what is mentioned in Manage custom app policies and settings in Microsoft Teams is enabled.

  
  


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  Wait another hour.

  
  


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  Quit desktop application, and start it again.

  
  

Now, finally, it works.