The license/key stuff shouldn't care. My guess would be there is something in the global save game that is expansion specific or part of the expansion directory is still there so it is trying to load the expansion assets.
For the 1st one, remove or rename the directory C:\Users\YOU USER NAME\AppData\Local\Zombasite\User\chars which will get rid of all of your save games including the global ones.
For the 2nd one, go to the Zombasite directory and make sure the Expansions directory doesn't exist.
Depths of Peril, Kivi's Underworld, Din's Curse, Drox Operative, Zombasite, Din's Legacy, & Drox Operative 2