I've plugged a USB in my PS4 containing my PS3 LBP2 save data, which LBP3 recognises.
It came up with a message before saying "We've looked through your profile and found LBP and LBP2 stuff, go to My Unlocks!" and I go there but the options below have a strikethrough.

http://i.imgur.com/BHTfamY.png




http://i.imgur.com/3CurSfG.png

That is where my LBP2 save file is located on my USB.

Any ideas?

I didn't need a usb to transfer my stuff over.
Maybe try it without the usb?

If you're logged into the same account you've played LBP1 & 2 on, you'll have the options to unlock the content.

Hope that helps!

I used the USB because PSN was down . I am on the same account now that I have Internet access and it is still crossed out.

uhmm. yea, transferring with a usb isn't going to work. this is the first time I've heard of anything like this coming up.

make sure that you have your latest trophy data uploaded on your ps3 before you do this.

if nothing seems to work out, you may need to delete your LBP3 profile and start over. you may have messed something up by trying to do it that way