Hi there,
Ive downloaded trial version of the last Corona and thats what I see after it was successfuly installed. I used alpha 6 before and everything was fine
I think you must to go to “About Corona Renderer /licensing” rollout and try to activate the demo version.
Yes, “invalid license” means “invalid license”. 
Activating guide:
https://coronarenderer.freshdesk.com/support/solutions/articles/5000564325-activating-corona
It also applies for the demo version, you only need to choose “activate demo”.
Thank you, the problem was easily solved while I tried to render:)