I am trying to install the flash update but the installer quits unexpectedly before it even begins.
I am running a Mac OSX version 10.9.5 with 2 x 2.8 GHz quad-core intel xeon.
Any help available?
That's very odd.
I'd start by rebooting your computer, then checking the filesystem for errors:
Disk Utility 12.x: Repair disk permissions
Then give the offline installer a shot:
Retrieving data ...