http://pastebin.com/nVP3gack

It looks like its crashing from looking at the facade sprite in JEI. It's probably not a rush for you guys to get fixed but is there a way to disable facades from showing up in JEI? This might be a nice fix for similar issues in the future.

It's probably not a rush for you guys to get fixed but is there a way to disable facades from showing up in JEI?

You can disable individual facades in the Facades.cfg config file. But I will look into cross-mod compatibility soon.

While we probably should add a more sophisticated check to detect, if blocks can be turned into facades. For example like C&B does it.

Here it is clearly an issue of XU2 not respecting the method contract allowing to pass null due to the parameter being @Nullable. Further null is actually being passed along by JEI based on the callstack.
Thus we are more or less just caught in the middle.

@whatthedrunk To fix this after updating to the latest revision, you have to delete your Facades.cfg.
AE2 will now by default not enable facades for blocks with extended block states (all of XU2's blocks have that). One can enable it on a case-by-case basis via the config, but in XU2's case, it would continue to crash.