Second-generation Chromecast and Chromecast Audio devices are facing a problem that prevents them from casting content. If you try to use an affected device, you'll see one of two errors -- either, "Untrusted device: [name] couldn't be verified. This could be caused by outdated device firmware," or "We couldn't authenticate your Chromecast."

Chromecast users have encountered an 'untrusted device' error affecting older generation devices, particularly the 2nd generation Chromecast and Chromecast Audio. Google has acknowledged the problem and is working on a solution,

If you’re one of the unlucky Chromecast owners whose “untrusted” device stopped working earlier this week, here’s some good news: a fix is on the way. As reported by 9to5Google, Google has issued a fix that should restore service to the stymied Chromecast streamers,