The license may have indeed expired!
However, the first thing to do is check if the license you use is Hardlock (USB key) or Softlock. If the license is secured with Hardlock, make sure that the Rockey4 USB key (the small blue USB key) is plugged into a working USB port on your PC, and that the green LED light is steady and not blinking or flashing.
If it is flashing, then you will almost certainly need to re-install updated drivers. If it is plugged in and the light is steady (not flashing) and you’re still getting the message, try unplugging the key, rebooting your PC, and plugging the key back in. If the problem persists, go to this FAQ and update the Rockey Driver.
If the problem persists, please contact AppliCad Support.
If your version is secured with a softlock or software key code, then you will need to renew your license and contact AppliCad Support to obtain a new unlock code.