No, you’re not the only one getting an error message on Twitter. Many tweeters from around the globe found themselves up against a “Could not authenticate you” notification.

Twitter did acknowledge a service issue, saying only that “Some users may be experiencing issues viewing and sending Tweets on twitter.com and Twitter’s mobile apps.” It’s not clear if the authentication alerts are related to that service issue.

https://twitter.com/ellejohara/status/466326464443736066