The game crashed on my friends Macbook.
crash-2017-12-28_21.16.txt

the exception seems to be "Caused by: java.lang.OutOfMemoryError: unable to create new native thread".

That always happens at the end of the start.

But there is:
net.minecraftforge.fml.common.LoaderExceptionModCrash: Caught exception from UniDict (unidict)
Caused by: java.lang.OutOfMemoryError: unable to create new native thread

and there is Memory: 4312239864 bytes (4112 MB) / 8489271296 bytes (8096 MB) up to 8589934592 bytes (8192 MB)
That should be enough. So why did that happen with Unidict?

oh, so seems that there is available memory. but unfortunately, I don't have any mac and neither money to buy one to try to fix this =/
on this specific case, the crashlog isn't enough to figureout what is happening =/

It only happens if Block Drops is present.
https://minecraft.curseforge.com/projects/block-drops-jei-addon

I think that that was overlasting the process.

well, I really don't know why it would interfere, but okay XD