i have a crash when placing blueprint on "ic printer"

java.lang.NullPointerException: Ticking screen
at net.minecraft.item.ItemStack.func_77960_j(ItemStack.java:217)
at mrtjp.core.item.ItemKey$.get(itemident.scala:19)
......
...

full crash log : http://pastebin.com/znMNHLLN

You should probably explain when you got the error

Caused because some mod is being stupid and adding a recipe with a null ingredient. Technically not my fault, but I can add a check to prevent this...

Fixed via 57cded5