Users who are administrators or Sub-administrators cannot be deleted.
Please revoke their administrative privileges before you delete the users.
When deleting an administrator
An administrator position cannot be left vacant.
First, please change the administrator to a successor user.
Related: Change the Administrator (Web Browser Version)
https://teachme.jp/8/manuals/51167056
When you change the administrator, the previous administrator is automatically designated as a Sub-administrator.
Please revoke the Sub-administrator privileges before deleting the user.
Related: Remove a Sub-administrator (Web Browser)
https://teachme.jp/8/manuals/51248881
When deleting a Sub-administrator
Please revoke the Sub-administrator privileges before deleting the user.
Related: Remove a Sub-administrator (Web Browser)
https://teachme.jp/8/manuals/51248881
Related
Delete Users (Web Browser)
https://teachme.jp/8/manuals/51167129