Critical "failed to add window command bar extensions" since last Studio 2017 update

Since the last update of Trados Studio 2017 we are having an annoying problem. When Studio is starting it seems to load the update manager and then chrashes with the following message: "failed to add window command bar extensions". Reseting Studio by renaming the Appdata Folder or project.xml  as well as repairing it with the installation wizard does not help. The only thing that helps is to reinstall, just to experience it crash again at some point (the next day in our case). We dont know what to do.

Happened on two different machines (Windows 10, Windows 8), all updates installed.

We need your help, what can we do?

Kind regards, Marie Christine