i have te the same problem

Are you using the creative port to spawn the ship? A quick fix would be to download the mission that spawns the ship either at a island or at the creative port docks

im using the creative and still it says its to big to spawn

You have to spawn it in the creative docks

I found a problem with your mission. The problem is that the ship spawns in the creative port, BUT his spawnbox slightly taps the shore. It's not even a part, just empty air, but it still refuses to spawn. You can move it diagonally a little bit an it'll work.