I am trying to install the latest Flash Player 13 for my imac. It starts to then stops and asks me to Quit DashboardClient which I have never heard of .
There is no such animal and I have nothing opened to quit, except for the Flash Player installer.
I am running a intel core 2 duo Imac with OSX 10.9.2
I have since found out that the offending item is widgets running in the Dashboard application.
What you do is go into Activity Monitor - select Dasboard- then select force quit, close all other applications.
Restart the installation process which should now complete then restart computer and it should be done.
I have never had to do this ever with any update , but it does work , I think (hopefully).