I had the same issue when installing my MMI unit. Initially, I had a loose connection in the climate panel which went away after properly reseating the blue connector. But I still had some errors in IHKA at which point I took it apart and redid the connection following what is explained in this thread:
https://f10.m5post.com/forums/showth...7#post27017547
It seems to be a common issue that seems to become a problem when this connection is removed/reseated multiple times because I never had this problem the first time I took apart the climate panel.