On Extensions tab, "Secret" is gone!

I am trying to set up a new SIP extension, I’ve always used the Extension tab, and the “Secret” to enter the password on the SIP phone. It has disappeared. There is a a new User Management area, has this replaced the secret? (It doesn’t seem to be working either.) Thanks!

Never mind, sorry, I restarted Firefox and everything is OK.

The Extension Module has a silly feature where you can click section’s title and that whole section will disappear.

If this happens again, look for the + next to the section, click it, and it will reappear.