sb_Gooniverse won't load

Hi, whenever I feel like I want to build a spaceship i boot up gmod and get to work. I go on flatgrass and build till my ship is deemed complete. Then I load up sb_gooniverse but theres a problem, I get stuck at the loading screen for hours and I restart my computer.

What may be causing this?

I was having the same issue, so I just stopped using that map. There are better maps out there. But if you have your heart set on playing it delete it and redownload it. Best I can say.