I "successfully" got the game to hang by trying to provide Otto the same Lock Data for a second time on the same visit where I picked up a key.
More specifically, I retrieved the Lock Data on Day Two, brought it to Otto's Cabin and asked him to make the key, returned to the locked house and retrieved Lock Data a second time. When I returned on Day Three to retrieve the key, Otto has it ready. When the conversation ends, I engage him in conversation again, and he asks if I would like for him to make a key.
When I answer in the affirmative, the game hangs. I was able to duplicate the bug.