Since this is a discussion and not a plea for help to mend a broken system I’m hoping that @anon42388993 or some other learned poster can help my unscramble the results below:
pfeiffep@Dell-1749:~$ apt-cache depends nautilus | grep Breaks
Breaks: gnome-bluetooth
Breaks: gnome-session
Breaks: gnome-volume-manager
Breaks: nautilus-sendto-empathy
Breaks: rhythmbox
pfeiffep@Dell-1749:~$ apt-cache depends caja | grep Breaks
Breaks: libcaja-extension
Breaks: mate-session-manager
Apparently both nautilus and caja, if uninstalled, will break something in UM 16 ???