Dears I am facing this issue in GCP playground.
Google Cloud Shell has been disabled for your account due to a violation of our Terms of Service.
Since many or most users have personal google accounts, please make sure you’re using an icognito window to open the GCP playground. I just tried this, and there’s no problem opening a Cloud Shell window when I do that. So just do it that way; it should work w/o that error.
Thanks for the reply. I got this issue on my office network and when I tried at home it worked without issue.