@Richard Linderman Thanks for reaching out to Microsoft Q&A, apologize for any inconvenience caused on this.
Based on the error message it more looks like to be a permission issue Could you please try checking by following the suggested steps and let us if you are facing the issue.
- Check that you have the necessary permissions to create a new Cloud Shell instance. You can do this by going to the "Access control (IAM)" tab in the left-hand menu of the Azure portal and checking that you have the "Contributor" role assigned to your account.
- If you are still having issues, try logging out of the Azure portal and logging back in again. Sometimes this can help to refresh your session and resolve any issues.