Google Confirms Fix in Progress for Second-Gen Chromecast Outage

A server-side issue caused by expired security certificates has rendered second-gen Chromecast and Chromecast Audio devices unusable, with Google advising against factory resets.

Second-generation Chromecast and Chromecast Audio devices are experiencing outages caused by expired security certificates, preventing users from casting content.
Google has acknowledged the issue and confirmed that a server-side fix is being developed to resolve the problem.
Affected users see error messages such as 'Untrusted device' or 'Couldn't authenticate your Chromecast,' with no workaround currently available.
Google has warned users not to perform a factory reset on their devices, as this complicates the restoration process; instructions will be provided for those who already reset their devices.
The issue is limited to older Chromecast models, and Google has reiterated that support for these devices has not been discontinued.