There seems to be all sorts of issues with these old ships. That's why I'm slowly redoing the entire line in vanilla where they can be modded if needed.

I dont know if its just me but when I try to spawn some of these it says that it some of the blocks arent in-game but I downloaded all of the mods that halo world needed

Exactly. Everything I make is meant to be smaller so more people can use them. Heck, even high rollers would not be able to run a full sized Athens-class carrier. Try building a ship that is about 5 km long!

It's supposed to be small. Just like all the others they are scaled down due to Space Engineers would just have a meltdown if you put all the halo creations he's made into the game.

I think if you trippled the size but overall its a great job!