I have the exact same problem, but with the Hitchhiker Storage Container. Edit: The first time I ran it I had 396 parts, the second time, I had 401, but I hadn't installed anything between those runs. Edit 2: Every stock part stops the loading. Edit 3: Almost every stock part stops the loading. Edit 4: Nope, Every stock part stops the loading. Edit 5:Nope, random parts stop the loading.