I’ve installed Unity 5.1.1.f1 and the message “Checking License - Unity is checking your license authorization” appears continuously. I’ve read a lot of posts about this problem and the solution was always to disable internet connection.
But my problem is : I can’t disable internet connection because unity is installed on a TeamCity build agent who is a remote server.
If you need to fill out a contact form, then make sure you include everything you can possibly think of about your system. (The message you posted on Monday doesn’t include enough info about your set-up. Does the machine have access to external servers?)