I'm unsure about if this persists in the betas, but if you bonemeal grass when it is being pushed by a piston the game crashes. This occured before and after installing a chunk border indicator behavior pack. The problem persists across chunk borders or completely inside a chunk. I first noticed the problem in one of the 1.12 versions, but now it is consistent. If an autosave occurs at just the wrong moment it will corrupt your world. I utilize this mechanic in my shifting floor flower farm so it is a important crash to me that needs to be fixed.

Using the attached design fill the despenser that is facing towards the grass block, and you can replicate this by spamming the lever.

Through the techrock server I learned that it was more than the game that crashes. It also crashes Windows Defender and many other applications that help with the security of your windows 10 device. I also found that it's actually caused by dispensing bone meal on grass period doesn't have to be moving. if you see this report PLEASE vote for it. It is a catastrophic bug that is dangerous to your PCs health.