Hi,
about node editor previews, you need to go to c4doctane Setting/Nodes, and disable the New style option, or material preview doesn't work in node editor:
About crash after closing Live View, in general, it happens if you have previously installed a XB (beta) version, please close c4d, then try to delete the oct.dat file, at the following path, the c4doctane preferences will be reset to default, and a new oct.dat file will be created on next c4d start:
/Users/UserName/Library/Preferences/Maxon/Maxon Cinema 4D R2X_XXXXXXX/prefs/oct.datIf not enough, please delete any c4d custom layout with c4doctane panels inside, and rebuild them from scratch.
ciao,
Beppe