I am trying to make a new account and there is already an account from the initial setup that I would like to use. I need to delete this old account so I can set up a new one with this email, but do not have the option to delete an application user after the upgrade to Single Sign On.
This issue has been resolved in version 4.99. All sites have been updated in February 2018. If you experience this error, please chat with support to provide the exact steps that were taken.