Cannot change my admin-user options?
 

I want to change a few things re my admin-user options. For example, I want to change the auto-thread subscription mode from "do not subscribe" to "Instant email notification."

In attempting to make this change, however, I received a message that ""This user is protected from being altered . . . "

I am the only administrator. At the time I sought to make the change, I was logged in as that administrator.

Surely I can make such small changes quite readily? how can I do that?