CO - 22 Not starting

 Currently I use CO 22 version 15.3.0 on Windows 11 ( updated to 22H2) - with a Dell XPS i9 desktop. I use a 1TB SSD (with apps) and a 4 TB HD (for data); video is NVIDIA GeForce RTX 2060 and 16GB RAM mem.

Since yesterday morning, CO does not start any more . When clicking the CO icon, its asking if the app is autorised to make changements to the system, and replying 'yes' closes the CO-window and stops reacting (all other apps work fine, and the computer continues running).

After many restarts of Windows, with and without my Norton 360 activated, I have deactivated (via my laptop) the active license on the desktop. After removing CO from my computer I tried to reinstall the app on the desktop, but without succes. After installing CO tells me I am not authorised!

Can you please asap tell me how to resolve this problem?