Cubase 11 not even starting after upgrade from 10.5 on Win10

Hi. I have been running Cubase apps for years on Win 7. (from 5 up to 10.5 ) . Needed to upgrade to Win 10 to run Cubase 11. So I did. Win 10 runs fine all apps working except Cubase. Cubase 11 not even starting and none of my older Cubase 8.5 or 10.5 wil run now. The Cubase.exe process just sits in the task manager. Any ideas anyone

If I leave Cubase startup alone for a few minutes it finally comes up with this message
“could not connect pos cubase”
I have re-installed latest elicenser as admin. doesn’t help
I can see all my licenses in eLicenser control ok.
Did eLicenser un-install then re-install again then ran as admin.
sees all licenses ok.
Then ran Cubase as admin.
Amazing Cu11 now runs.