Cannot login to Gnome after update

Loging out of KDE and into Gnome I get this error message:
“Oh no! Something has gone wrong.
A problem has occurred and the system can’t recover. All extensions have been disabled as a precaution.”

If I wait a minute or so I get this popup error message:
“No system tray detected on this system. Unable to start, exiting.”

Fond the solution here: post 26 by sankeytm Thanks