When I cut a lot of grass quickly the game crash. I tried it several times and always crash. It doesn't happen on the stable version (1.7.10).
Description: Unexpected error
java.lang.IllegalArgumentException: Cannot get property azh{name=variant, clazz=class aqs, values=[sunflower, syringa, double_grass, double_fern, double_rose, paeonia]} as it does not exist!
at ayx.b(SourceFile:120)
at aqq.a(SourceFile:280)
at bnw.c(SourceFile:154)
at bnw.b(SourceFile:71)
at bnw.a(SourceFile:48)
I haven't been able to replicate in 14w28b either.
Possibly fixed!
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Still present in 14w28a.
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I can replicate this, but not reliably. I haven't been able to nail down the specific circumstances that cause it beyond "punch grass".
I submitted the crash report from the game, the short summary looks like this: