In October, Windows LTSC activation was restricted due to a licensing error on Microsoft's part. TU Wien has since introduced a workaround (see news from November 19, 2021). Microsoft has finally rolled out a fix for the issue with the March updates. However, this includes major updates to the activation server and a reset of the activation data.
It may therefore take a few attempts over the next few days before an activation works. Therefore, if you are not successful with a Microsoft activation, please try several times with a few minutes between each attempt. As soon as the internal counters have reached the minimum level again, the service will be available again in the usual quality.
The LTSC workaround will remain in place until further notice. A de-installation can only be started after the updates of the production servers have been carried out and no further problems are detected.