I have the same problem after an upgrade to 15.10. running a gnome3 session here.
One other report of this problem is here: https://askubuntu.com/questions/562355/seemingly-random-authentication-is-required-to-change-your-own-user-data
The "solution" posted there however doesn't seem right to me (preventing PolicyKit Authentication Aagent from starting).
I have the same problem after an upgrade to 15.10. running a gnome3 session here.
One other report of this problem is here: https:/ /askubuntu. com/questions/ 562355/ seemingly- random- authentication- is-required- to-change- your-own- user-data
The "solution" posted there however doesn't seem right to me (preventing PolicyKit Authentication Aagent from starting).