App crashes when Multi C in Mixermodul selected

Hi,
well, so far i have to say, well done guys!
… only a little manual reading was necessary.
I do not know how, but pressing the Multi C button in the Mixer Modul causes a crash of the app.
It has worked in the beginning… two days ago.
Latest App versuon, latest server. IPad Pro second generation
Neither USB nor Wifi do a change here.
Any ideas?

Thank you very much in advance.

Edgar.