Hi Martin Moller,
Welcome to the Microsoft Q&A Platform!
Check Existing App Registrations:
Go to Azure Active Directory > App registrations in the Azure Portal.
Look for your app. If it’s missing, proceed to reset.
Delete Faulty Registrations:
Check the Deleted applications section to restore the app.
If not found, delete any references to the non-existent AppID in Azure AD and Partner Center.
Create a New App Registration:
In Azure AD, create a new app registration.
Save the AppID and Client Secret.
Update WNS Configuration:
Go to Microsoft Partner Center and update your app with the new AppID and Client Secret.
Update Notification Hub:
In Azure Notification Hub, update Package SID and Client Secret under Windows (WNS) settings.
Test Push Notifications:
Verify that WNS push notifications work after the updates.
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