Audio problem: In "Silly Love Songs" during the final song You can hear Blaine singing "I can explain." but in a couple of the shots he is lip-syncing to the "I love you". Next shot is he is back to singing his solo part.
Audio problem: Jeff summons Abed and Troy to meet together, saying "this has to stop," to which Abed replies "tell him." But the audio was cut abruptly at the start of his sentence and we can only hear "ell him."
Audio problem: In the final scene when Cleveland says to Terry "I'm gonna get paid and you're gonna get laid", they both start cheering. But when it comes to the wide shot, Terry is still cheering but his mouth isn't moving. (00:19:55)