We checked the Event Viewer (Application Logs, Windows Azure Logs) but we can't find any errors or warnings regarding this issue. So we have to assume there is an issue with the app. The Text message and Phone call option is working perfectly. We've tried manually adding an account instead of via a QR code.We've tried several versions of the MFA app (latest 6.4.8, 6.4.7, 6.4.5 and 6.4.4).We've tried several Android phones (Samsung Galaxy S8, Samsung Galaxy J5 and OnePlus 6).Please contact your local IT administrator to resolve the problem.' This will fail after about 15 seconds with a generic error message: 'Unable to add the account. Unexpected error.When the QR code is scanned there will be a notification saying 'Activating.After this we're able to use the camera to scan the QR code.Then we press the 'Work or school account' option.When opening the Microsoft Authenticator app we press on the '+' symbol to add an account.The customer is using a on-premise Multi-Factor Authentication Server (version 7.2.0.1). The customer has about 1500 employees which are all experiencing the same issue. We're having trouble activating the Microsoft Authenticator App with a specific customer.

Ms authenticator app