POS Crashing and won't open

Hi, I have several POS stations that are crash the POS quiet of few times a day.

I am not sure what cause making POS crash. But when I exit out of the POS and reopen, it won't open. So I go to task manager and kill the SOPOSUSER.exe process. Then it will open the POS.

I am trying to find out what makes this problem occur? Does anyone knows why?

Thanks