I realize there is an issue already out on this, however it is now 4 months old and no update has been given on it. This issue was also brought up recently over on JER's GIT. I'm getting crashes which are pointing to IR when attempting to fully profile a world with JER. Crash Log

Update your java to start with, this will save you bothering IE when that starts crashing the game.

Using the latest JER alpha build + forcing Twitch to use a custom Java install does work. Just wish there was a way on Twitch to force it to use it 100% of the time... and I wish that Twitch would keep Java updated as well.

Thanks Larky. Now I just need to go talk to JER about the fact that I can't actually see the ore gen on the latest Alpha.

My apologies, I lied. Issue persists on latest alpha with a custom Java install running. Got lucky with it once and thought the issue was solved. Has now crashed 3 out of 4 times. New crash log