Game Crashes Randomly. Plz fix.

I was exploring my world. When I sprint, walk, or do something, my game crashes. I was in my hidden storage room then I close my piston Jen door. I ran outside to my XP farm but then it cashes. Then it put me back to my hidden storage room. When I tried to go back to my xp farm, I got trapped in my storage room with the jet door closes. I didn't happen all the time but happens randomly. It's soo annoying.