I have been using a smooth stone generator for acquiring large quantities of stone to build structures. However, whenever I go to the Nether and then return and start up the stone generator again, the game crashes. To recreate issue, take the following steps:

1. Start a new world and create a stone generator similar to the attached photo

2. Create a nether portal and travel to the nether

3. Return to the overworld and start stone generator

The amount of time spent either in the nether, or in the overworld after returning, makes no difference in outcome. The use of a button vs a lever has no affect on the outcome. Using or not using a redstone clock to automatically cycle the piston makes no difference in the outcome. All of them lead to game crash.