I have the same issue. The taskbar is not operabel. Windows icon and the programm icons not operable (not klickable and not with the windows key)
Key combination and short cuts etc. work (Windows+E;...)
Everything in the window is also operable, excell etc.
With Strg+Alt Delete I can Logout the usere but before I have to force shut down of a task which sais "taskhost...install reboot required".Or similar.
Then I can login again and all is fine. This happens since a few weeks and not very often. (However when I look into windows update it does not say reboot required)
I tried to find this task in the taksmanager but could not find it.
I use Defender offline (just scan from time to time) parallel with Avast Antivirus realtime. At one step I though it could be the update of Defender definitions which is are stuck.
When I can I will try to make a printscreen of the task when I have the problem again. This task is stuck.
I have 1709 (Build 16299.125)
I have here the text of the Tastk which is stuck preventing logout, shutdown and certainly blocking the task bar:
Tast Host Windows
Vom Aufgabenhost werden Hintergrundaufgaben angehalten
\Microsoft\Windows\Plug and Play\Device Install Reboot Required
On my other computer I made today the latest 4 updates and now it has the same problem. :-(
On both I have not plueged in anything new.