Von Neumann asked it what the answer to the invisibility problems could be. He learned that he had to go back and do his homework in metaphysics. The nature of the problem was that the personnel on the ship were not locked to the zerotime reference of the ship. Humans are normally locked to the point of conception as a time reference, not a zero-time reference. The time stream lock allows the person to flow in synch with the system so interaction is possible.
Time locks are fragile.
All the power of the project disrupted the time-locks of the people on the deck on the ship. When the ship came back in time, the people didn't come back to the same reference. Von Neumann realized that he needed a computer, as well as some knowledge of metaphysics in order to be able to lock the time reference of the people to the time reference of the ship. He built a computer in 1950 for the purpose. It was ready to be installed in 1952 and a test was performed in 1953 that was successful.