Having the same issue.
I'll send the notes here and please respond rapidly as I really want to play the mod with my friends.
I only have Alex's Caves and citadel downloaded. I repaired everything reinstalled java, and even Minecraft but i keep getting the same error code.

hs_err_pid27688.log
@AlexModGuy

dupe #229

this doesn't fix the problem
I already checked #229 several times and theirs no solution as it seems that citadel is the problem making it impossible to play alex's caves @AlexModGuy

I don't know tho im just assuming citadel is causing the problem

Update your AMD drivers on their website.