Hold on, are you building the rocket directly? Don't do that. The V3, Dreadnought and Cruise missiles are all unbuildable for a reason. If you are using a spawning building or unit, we'd need to see the building's code, not the rocket's.
Edit: Just realised that you have TechLevel=-1, so ignore what I said about building the rocket directly.
Edit: Just realised that you have TechLevel=-1, so ignore what I said about building the rocket directly.