I followed the directions on the PIN2DMD site.
1) Connect the your controller to power, if not already connected.
2) Connect the STM board using the microUSB cable to your PC.
3) Copy the keyfile in the same directory where your pin2dmd.exe is located.
4) Start the pin2dmd.exe tool without any option.
It worked fine for a long time then the activation issue happened. I do have a key and it no longer matches my display. A couple of weeks ago I deleted everything from the controller and started over using the original key. Now when the activation code comes up, it is different than it was originally. If I need to purchase another key, that is fine but I want to be sure there isn't anything wrong where I would need to continue to purchase additional ones.