Hey there, thanks for the tweet — help's here! Does your Chromecast look like a thumb drive, hockey puck or does it come with a remote? What country are you currently in?
Jumping in – is this happening across all devices? If you haven’t yet, we recommend restarting your pc/mobile. Also, updating the app/browser to its latest version might help. In case the issue persists, share a screenshot of the error you’re getting so that we can further check.