This is how you fix this issue:
You need to login to your Microsoft account and go to subscriptions...
you should see your office 365 subscription listed
it will list the computer name you have assigned to one of your available licenses
you need to delete that machine from the list
then click install and let it run through the install process
when its done - you will see a message - all done!
you must then reboot your computer
and then try to login to Outlook, word, excel or which ever program is giving you the unlicensed error or red band on the top screen -
if the red band is still present - log back into your Microsoft account and click the install button again
you may have to try this solution a couple of times to get it working
the good news is that this does work - just try it again if it fails the first time.. it only takes a few minutes to run it again if it fails
I am sure this will resolve your issues - have a nice day!