did the default port get changed to 55675?
i noticed my remote/controller style setup stopped working a few days ago.
I started getting POS errors too, so i redid my mn setup without specifying port 11994, now it shows up on the list as using port 55675
so i recommend redoing all your masternodes with this new default port to see if it fixes it. and yes the window's client crashes for me too when I try to have masternode.conf. possibly related to the default port change problem.