We are currently experiencing issues with a custom Teams application installed on our tenant. The app is called Teams Manager. We are not using the app from the Microsoft Store. It is a custom app that we uploaded using the APP manifest. The app server is hosted on Azure in the same tenant.
The problem is that the app does not load and returns a 500 error. We have installed the same app manifest on our test tenant and from there it works fine. Since it works from the test tenant, we believe it is not an issue from the app server hosted on azure.
I have tried to disable all security features such as Defender for Cloud on the Prod tenant but it does not work. The 500 error is being thrown by the backend server calling the graph api. I belive the graph api is taking too long and that is why this is happening. But since on the test tenant we have the same amount of groups so the response time should be the same.
Does anyone have any idea what the problem might be? It could be the Defender 365 settings or something else. Regards
I have tried to disable all security settings on the Office 365 portal.
I already have two ticket open with Microsoft, unfortunately they do not really show a willingness to help. They are still looking for the problem at Azure App service because there the 500 Error is issued. I have tried to explain to them that the error messages only occur when the request comes from the Teams App installed in the Prod-Tenant. From the Teams app in the test tenant it works without any problems.