Khdesign the DF019 error indicates the the MainMenu.nib file has been removed from your installation of the Extension Manager? Do you use any type of system optimization utilities which remove additional language files?
Also have you tried the steps offered by Ned in message #1? In specific the steps in http://helpx.adobe.com/creative-suite/kb/unable-apply-extension-manage r-update.html should allow you to resolve your difficulties.