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 This could be caused by outdated device firmware," or "We couldn't authenticate your Chromecast."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,

It's been a pretty frustrating week for owners of a 2nd-gen Chromecast or Chromecast Audio, but a fix for the bug that's rendered these devices inoperable is now rolling out – just as new issues appear for the newer Chromecast with Google TV.