If:

• there is a dispenser or dropper being automatically filled or emptied
• there is a stockpile switch pointed at it
• the stockpile switch is connected with no delay to the dispenser/dropper

then the game crashes when the stockpile switch's threshold triggers and activates the dispenser/dropper.
It doesn't happen with content observers, or when the dispenser/dropper is filled or emptied by hand.
SImple example setup:

Duplicate of #1702