In both the 2.0.21 and 2.0-pre18 versions for 1.7.10, my game crashes during startup with the following error:
"cpw.mods.fml.common.LoaderException: java.lang.NoClassDefFoundError: binnie/extrabees/apiary/TileExtraBeeAlveary".
However, in the path binnie/extrabees/apiary, there is a file called TileExtraBeeAlveary.class.
What's going on here?

Thanks for the report!
Please make sure to remove any Binnie bug-fixing mods like BinniePatcher, they are not needed with these new versions.
If you still crash please upload the crash log to https://gist.github.com/ and link it here.

the only mod I installed was the core Binnie's Mods. Here's the crash log:
https://gist.github.com/Alex33212/343b50f113ce41f605846f7544179822

Hm. Are you change class with some bytecode editor?
I'm playing with 2.0.21 version and I don't have any problems.
Can you remove all mods and check it with Forestry and Binnie only? And gradually adding mods. Maybe some mod patch the code...

well, given that I'm adding Binnie's Mods to the Tekkit Legends modpack, I can't really remove mods without seriously messing things up.

Oh, I see you're using Forestry 3.6.
This new Binnie's only works with the latest Forestry, 4.2.16.

@KorDum for 1.7.10 Binnie's please add a minimum required version for Forestry.
Here's an example from 1.11.2
https://github.com/ForestryMC/Binnie/blob/master-MC1.11.2/src/main/java/binnie/core/BinnieCore.java#L61

@mezz I'll do it, thanks!