At the moment there can be problems in myOperations Portal environments if the Microsoft Security Update KB5007206 has been installed on a domain controller.

As a result of the updates, Kerberos authentication no longer works correctly in a multi-hop scenario, as is normally the case with myOperations Portal accessing the Microsoft Service Manager. This means that users can no longer log in to the Service Manager via myOperations. A description of the error scenario can be found in this Microsoft support article.

With the help of these new updates you can fix the errors:

Source (German): heise Online