So I just bought a Playstation 3 about a month ago, The Last of Us being a large reason I bought one. (With other great Playstation exclusives in mind as well such as Uncharted and InFamous.)
To my dismay I've reached a part in The Last of Us' superb single-player experience that I have deemed to difficult to tackle at this moment in time leading to my decision to put it off to another time; but I don't want to stop playing a game with such engaging gameplay, so I decided to try out the "Factions" portion of the game. After multiple attempts of trying to connect recieving the same, "Error Syncing Level's" message over and over again, I try to check the interwebz for an answer to my questions. I reset my system and router, reconnected to the internet, signed out, redownloaded the patch and online pass, and all the other suggestions that others have given me.
After letting my girlfriend borrow the game for a few days, she returned it, and I got well passed the part that I was previously stuck at; but I still wanted to try the multiplayer portion of the game that I paid $60 dollars for, so to my surprise I chose the factions option, and it worked! I got an entire 6 hours of gameplay from it and I could not be more impressed with Naughty Dog's prowess in game development, so kudos, Naughty Dog.
Although, being a somewhat busy man, I had to go to work to make sure that I can pay for bills and such. Coming back after spending some time with the girlfriend, I came back to play, and once again, the "Error Syncing Level's" plagued my existence once more, and has continued to the time of this topic posting.
It is with a heavy heart, and as a fellow gamer that I ask for help: What can I do so I can enjoy this game for the many months to come until I can pick my next-gen console up from the store?
TL;DR: How do I fix, "Error Syncing Levels?"