When trying to create a subscription on some of my customers calendars using MS Graph (https://graph.microsoft.com/v1.0/subscriptions), I get this error for a few users
{
"error": {
"code": "ExtensionError",
"message": "Operation: Create; Exception: [Status Code: ServiceUnavailable; Reason: Target resource 'xxxx-xxx-xxx-xxxx' hosted on database 'xxxx-xxx-xxx-xxxx' is currently on backend 'Unknown']",
"innerError": {
"date": "2020-11-27T00:12:53",
"request-id": "xxxx-xxx-xxx-xxxx",
"client-request-id": "xxxx-xxx-xxx-xxxx"
}
}
}
The documentation https://docs.microsoft.com/en-us/graph/errors suggests that ExtensionError means that the users calendar is on an on premises Exchange Server, but I am able to read and write the events of the users calendar, so I don't think this is the case. Any other suggestions?