Windows Server 2012 R2 "License state unidentified - reinstall authorization"

[marzvt]

One day this message popped up after Nitro had been working perfectly for months. Now Nitro won't work and I cant get rid of the message as long as nitro is installed. I have uninstalled, rebooted, re installed several times. Manually removed all the files I could find and the error comes back as soon as I reintall.