The standalone game from taleworlds download (vanilla) does not work (Incorrect serial key). The game through steam works.
Mods, specifically Floris (that's the only one I want) does not work either on steam or standalone. On steam through WSE I get the same error (Incorrect serial key) and on standalone installation I can't even register vanilla (didn't proceed to install Floris at all).
I hope this clarifies a bit the situation.