It sounds like you might be trying to open the .rpa file instead of running Signed_and_Sealed_With_a_Kiss.exe., or the equivalent for your OS. The .rpa file only sits in your game folder, and you start the game the normal way.
I deleted the expansions & re-downloaded version 1.2 game, this time opening it without any of the new expansions first to see if it would open by itself. Then trying to force it to open by right-clicking and choosing "Open" rather than just double clicking
