Missing tweets? It's a bug that Twitter is investigating (update: tweets restored)

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.

Update: As noticed by The Verge, Twitter has announced that the error's been resolved and that it's restored the missing tweets and their respective favorites and retweets.