Our team uses https://browserstack.com to text across different browsers/devices. Recently I've been unable to get past the login screen with the following message:
Usually, waiting for a few minutes would resolve the issue; if that doesn't work, I advise you to try using another network; this can happen when your network is emitting too many requests.
Also, can you please let us know your browser and its version? Your location can play a role as well.