I have had the same problem except nothing works and sadly no reply from Steinberg support.
The ‘No Valid Licence’ messages started after upgrading to 12.0.40. There were no problems with the upgrade from Cubase 11 pro to Cubase 12 pro.
The latest elicenser correctly says
I have updated Activation Manager to 1.4.0.843 and reinstalled. No luck.
It says ‘Activation Limit Reached’
![Activation limit reached cubase steinberg|690x486]
My account says I have activated on 3 machines. But I haven’t. I have activated on a MacStudio (which works) and the Windows 10 PC which contains most of my projects and won’t work with the update.
(I don’t understand or recognise the codes for the 3 machines which my account says are activated. They are 10 digit codes - in hex?. Are they MAC codes?
Can anyone help please?