That has nothing to do with the bob's adjustable inserter it seems. The bug is especially odd since the function you receive an error from is called from a function which should have broken first. And from the looks of it the error should occur after any gui click (from modded entities) not just the adjustable inserter gui.
I have opened the version and I've tried it with bob's mods and it works just fine for me?
Logically your crash could occur if you have some mod which adds machines which craft recipes (assemblers) but aren't craftable themselves.
