Sorry, a temporary error has been reported by Google's servers.
To fix this error you need to sign out from Google and sign in again:

1. Go to https://myaccount.google.com
2. Click your profile icon in the top right of your screen
3. Select Sign out
4. Refresh your browser and try again

If that does not work, it might be that your cookies are corrupted in the borwser, so clear up your cookies and try again.
If the error persists, then try starting Chrome in incognito mode and re-trying the login.