This is a known issue, when you have not restarted your machine in awhile and activate your license. Our software has a hard time capturing your username. This then saves your activation as:


MACHINE1\


instead of 


MACHINE1\User_1


This is a rare known issue, so you will have to contact support to have them release your license key for reactivation. 

Please make sure you REBOOT your machine before you activate again. This will resolve the issue from happening any further.