Twitter has solved the mystery of some vanishing tweets.

And not just any tweets, but some of the most-shared over the social network. Users had been reporting that some tweets were missing, including the viral selfie taken at the Oscars with Ellen DeGeneres that was retweeted more than 3.4 million times at one point.

Cory Monteith's last tweet before the Glee actor's death was also missing. Various media companies began noticing some of their tweets were gone as well.

Twitter says it was a bug that kept some tweet from showing, but they've fixed the issue and all the missing tweets should be back.

--Rob Archer