Dr. Trevor J. Hutley wrote: > "The system extension > System/Library/extensions/System.kext/Plugins/Mach.kext was installed > improperly and cannot be used. Please try reinstalling it....." Mach.kext is part of the Core OS. If you play with it, make sure to keep a backup of the old version. I could be wrong but i think this file only gets updated with system patches / installs. Curious indeed. Other than getting the message do you get any issues? -- Tarik