I have a user that has a 2 seat license or whatever it's called for Creative Cloud. She mainly uses a MAC machine, and frequently uses a Windows machine. SOmetimes when she goes to start ADobe DC it will tell her that she can only be logged on from 2 devices and click this link to view where else shes signed in from. Low and behold, it only shows the 2 places she is signed in from. If she selects one and tell it to sign off that one....it does nothing. If she signs off of one, and tries to sign back into the one that gave her the message, it still says she is singed in twice and doesn't let her sign in.