Wiping your device will result in the TD and the licensing server seeing it as a new device. If you've installed your personal license on 3 PCs and you didn't explicitly remove the license from any of them, then when you try to use it on your freshly wiped device it will be seen as PC number 4 and won't work. The solution is to either (a) remove the license from your other PC(s) or (b) email support@thetournamentdirector.net and I can look into it.
To remove your license, press the Register button on the Game tab and then press the Remove License button.