[Discuss] Settings no longer works in Ubuntu

[Murray Strome]

This is the information provided by sysinfo:
System: Ubuntu 15.10 (wily)
Gnome:3.16.2 (Ubuntu 2015-09-15)
GCC Version: 5.2.1 (x86_64-linux-gnu)
Xorg version: 1.17.2 (30 September 2015  09:08:47AM)

There two options for System Settings:
The first has an icon like a gear cog with a red wrench. When I click on 
it, a window comes up very briefly, then disappears.
The second has a square box with a gear cog in the middle. When I click 
on it, on the task bar, it has a message:
Starting System Settings
    then this disappears after a few seconds. When I first tried it, it 
said something like an error occurred.

I tried rolling back to an earlier kernel but that did not work either.

Any idea as to what has happened?

I did replace my monitor -- I don't know if that has anything to do with it.

Murray