This afternoon Twitter users started noticing that they couldn't get to certain tweets, including Ellen's most-retweeted Oscar selfie. From Major Nelson to Justin Bieber, "Sorry that page doesn't exist" is all that exists if you try to link directly to the missing posts. According to Twitter Support, a bug is to blame and it is investigating, although there's no word yet on when the posts will be back.
The Tweet display issue has been resolved. http://t.co/19sKkq6wk4- Twitter Support (@Support) March 26, 2014