Steps to Reproduce

1. Open the mod's settings
2. Set the speed to 10%
3. Shift-click the cobblestone
4. Shift-click where the cobblestone will land
5. Do step four again
6. Crash!

If the steps above are confusing, please watch this video: https://youtu.be/rA0M2eegkLM

I have same issue, it's not only in slow animation. Because it still crash at animation speed 400% when I quickly crafting.
It seems that it is the code's problem.

@FlameFire26 I assume it has not to do with the speed but with the amount of animations it has to do. I only used a slow speed to demonstrate.

#57 #61 #62 are all this issue

same here