Here is a link to a crash report:

https://www.dropbox.com/s/4tzyy7h9o5urlwm/crash-2015-04-19_16.26.53-client.txt?dl=0

I guess something is up with Applied Energistics..
I will do some more testing though.

Reverting back to 0.7.5 solves any crashing.

Update AE2.

Oh new version isn't compatible with stable release. Il update to rv2 once it hits stable. If that is all it is, then might aswell close this? although you will probably have some other reports.

Open the issue if the bug still persists :)