the Austrian empire was pretty diverse. So WI in order to try reduce ethnic tensions, somehow a language was made from mixing together German, Hungarian, Czech, Polish, Croatian, Romanian , etc. And this language is used as the official language. Could this work and if so, How would this effect ethnic relations within the empire, and the nation as a whole.
Edit: when I say official language I mean it becomes Lingua Franca, like English in Nigeria or India.