The PC*Miler licensing uses a check-out / check-in form of licensing. When Profit Tools opens it checks out a PC*Miler license and when Profit Tools closes it checks the license back in. If Profit Tools crashes, or is disconnected from PC*Miler before the license check in is completed, the license remains checked out. Once this has happened, the only solution to this is to run the PC*Miler license reset utility to release all the licenses and start with a clean slate.
ALK PC*Miler provides information about the reset process on their support website.
ALK PC*Miler provides information about the reset process on their support website.