Fixed #1742 (Cargo computer stuck on "Invalid Request")

The only way this could happen is a runtime, and the "Invalid Request" message was there to provide an IC explanation for it not working. Sadly, whoever made this did not take in account that the "go back" part would not be printed if the proc runtimed.

No idea how it would runtime.
I'm guessing it is because SO is null, somehow. Add a null check here and remove the other changes.