I had similar problems and discovered:
• Running the Stand-Alone versions of PCBnew and Eeschema always crashed and closed if I did not place footprints/symbols (in other-words, if I simply opened them and closed them, Crash.
• This did not happen if running them from the Kicad Main Panel.
• In another post (here), I suggested solving slow speed of loading footprints. It turns out, the same ‘observable’ aspect part of the solution (for me) appears to also take care of this problem (can now close without adding footprints/symbols - No Crash!)
Before doing anything, I suggest running “Kicad.pro”, not PCBnew or eeschema standalone’s. The Main Panel presents PCBnew and Eeschema Icons to run them…