Normally when you put items into the encrust slot it says you can only put in armor/weapons. However lockpicks do not get the message and instead crash the game.
I... why would you do that? But seriously, I can tell you why is this happening, Aquason. It's simple - that's because lockpicks do not exist. Don't worry, there will come time when you will understand what I just said.
I was wondering what happens when you put something that isn't an armor/weapon into the encrusting thing. I just so happened to pick 6 lockpicks. Crash. Checked to see if the hotfix fixed anything like that. Saw nothing. Got the full patch. Tried it again. Crash. Tried other encrusting things, seeing if it mattered that I didn't have an anvil or if it still crashed if I had the encruster. Crash again. Post the bug.
That explains things. But seriously, don't test things on lockpicks if you can help it - they don't exist in the data files (being hard-coded instead), and thus the game doesn't know what to do with it, because it's trying to query the data files and they return nothing (because lockpicks do not exist, duh).