If you are experiencing random freezing and crashing while trying to play either School Days or Shiny Days, this may be caused by a few different issues. First, try the following most common problems & solutions:
If you've ruled out all of the above possible issues, then there might be a CPU stability issue. But, there is a workaround for this problem:
The above workaround forces a single CPU thread to focus on the game, which helps bring stability for certain CPUs. You will have to apply these settings each time you wish to play the game.