program crashes on dispenser with bonemeal use

After the 1.13 update, my test world now crashes whenever I try to use a setup that uses multiple pistons pushing a 7x7 grass platform back and forth. Below this grass I have a dispenser facing upwards to dispense bonemeal to grow flowers. This worked fine before the update. I lowered my settings, but it doesn't help. The game crashes completely and closes. I disconnected the dispenser and the pistons worked fine. But when I load bonemeal now and start the redstone, the game crashes.