Hi NatalieDBSC
Thank you so much for your post and sorry to hear that you were not able to delete/removed a user. You must be the company file administrator, or a user assigned the Administrator role, to change user access. If you don't sign on as an administrator. Please see Set a user's online access level for more information about the Owner's access level).
To remove access from a user who has been assigned the Administrator role, you'll need to deselect the Administrator role and select any other role, e.g. Banking, then click Save. You'll now be able to select the Inactive User option.
Please do let me know how you go on this.
Regards,
Earl