this level is one of the sub-level first part of the story where i have to release oddsock.
its that car building/racing level(i dont know the english name for that)

How its broken: when i go in there i just spawn in empty space and when i fall its bottom i will find small material/objects which belongs to that level so i think its baddly broken to me
when this happened first time just before that my game crashed and when i started it again that did happend . I have PS3 edition if that helps
can someone fix that PLEASE

There should be a way for you to restart an adventure in story-mode. This way, you can fix broken levels.

How i can do that?

you can't i just said there SHOULD be.

If you didnt progress to far in your story, you can delete ALL LBP3 data on your playstation and reinstall the game.
This should theoretically help, but wait a bit longer, maybe someone have better hint what to do.
There was something similar about the bridge in manglewood.
It have save logic tweaks on it and if broken, then it saves in broken state.
It was written that only deleting and replaying story helps.
If you came pretty far in story, then it would be pretty painfully to delete all the data.
(That means loosing everything what is saved like progress in DLC storys)
For that i hope that someone have better hint than that.

Actually you don't have to delete all of your data. You just need to delete adventure progress. Everything will stay except adventure progress and quests but you will still have prizes collected from adventure mode. It's possible for both PS3 and PS4.

How do you do that?

I'm not sure if there's a way to delete adventure progress directly in the game, but you can go to Save Data Utility under the XMB and there's something in there called something similar to "Adventure Mode Progress" (if not the same). Press the triangle button on it and select Delete. I can confirm that these instructions work for PS3, but PS4 is probably similar.

Something similar happened to me, but it wasn't as serious. The guy that always appears near the stores would be invisible, but the dialog was still there.

Thank you kubac2000 and Fox your solution helped me i just have to play a storymode again but its nothing

You're welcome! Always glad to help!

You're welcome

Actually months ago my friend had the same problem so I advised him to delete adventure data. He had to start the adventure again but he could finish it now.