If you don't bother reading the backstory then scroll down below it.

Basically what happened, is that my friend joined and I wanted to show him a project I'm working on.. I was off the PS3 later because I had a dinner and when I came back there were some stuff he placed and he left. So for saving purpose, I deleted what he had left, but before that I captured them, because it was a some sort of glitched Sackboy decals as a decorations, so I really liked it. Then I waited for the game to successfully save object, because I knew when I would save and quit level at the same time it'd pretty much erase my level, because of bug I've known already. Then finally I did that afterwards. When I came to edit my level another day, the game forced me into play mode, because suddenly - I don't have Spongebob Squarepants DLC! I asked my friend, but he claimed he doesn't have that DLC, so (scroll to Possible Fix)

In short (for those who don't want a back story), my level has been modified with DLC I don't own so..

Possible fix: I need somebody I can trust who has DLCs I wrote below, so I can share my level to that person so he might go to Create Mode and see what's the cause and delete it, or otherwise if there's nothing DLC related, capture everything in a level, create a new one and place all of this there and send me a level back so I can happily edit this level again.

Required DLC:

(Possibly) Move Pack, since I use Sticker Panel
Cross Controller/Sci-Fi Pack - for Radar Tags
Spongebob Squarepants Pack - that's the one I want to be deleted from my level.

My PSN is kubac2000, I play LBP3 on PS3

Got all of that.
I'm in.

Thanks for wanting me to help but I guess resetting the game fixed it, because I got back today and I can edit my level again It turned out to be some random glitch I guess.. lol

So yeah that makes sense, if we both don't own this DLC xD

Cool that you solved it!

Welcome guys,i have a problem with level names - Contraption: the case of the clock.When i built my car i cant start the game.I just dont know how to say this.I will start from beggining.When i get into the level i coming to "place where we can creat our car".When i crated my car there should be place where i can start my race,but this "doors" to level disapper or something like that and i cant start playing this level.Pls help me guys and developers with this problem cuz i cant pass all level for 100%

Ok dude.

That's weird you're posting to my thread about it but maybe try deleting Adventure Data either in Save Data Utility on PS3 or somewhere on PS4. Don't worry the only thing that it does is resets your level progress in Adventure. Sure you have to start it over but this can also fix issues occured by Object Saver (for ex. the center of the Manglewood hub which was missing its level link) This also doesn't reset all of your stuff collected from Adventure so you don't need to be worried about it as well.

Hello,i have problem with lvl in LTB pls help

kubac2000 u are from support or not?And if i will delete all my progres i will have all things which i pool?

I don't know what you mean by "which i pool" but if you delete it everything you've created and collected will be safe. Only Adventure progress gets reset. I helped in the same thing somebody about year ago and it worked for him.

And.. no, I'm not from support whatsoever. I'm just a player or creator if it comes to LBP

Ok thx kubac thx u from your help,pool i mean took or got i should say.Can u tell me where i can delete all my campaign progress?

On PS3, in XMB (PS3s main menu) go to Games > Save Data Utility, and look for 'LittleBigPlanet 3 Adventure Save Data' press Triangle on it and choose Delete.
On PS4 in Main menu go up and choose Settings. Go to Application Saved Data Management, then choose where is your data located (usually in System Storage) then choose Delete. Find 'LittleBigPlanet 3 Adventure Save Data' and delete it.