Terminal Install – Guide to Installing .pkg with Terminal

The update did not work for me, as I had already run it. It broke after the update. I still had the problem. In Finder, I could see that the file extension icon was not the gold/tan box icon that goes with Installer. There are two ways to do this. 1) In Finder, right-click, or get to the property window, and "Open With" and navigate to /System/Library/CoreServices/Installer.app. There is a checkbox to always open with this app. -or- 2) Open Installer itself and drag the mpkg file into it. Run the installer.

Both of these should run, and also change the mpkg icon in your Finder.

The package contains some files to be installed somewhere in the file system, not necessarily in ~/Library/Application Support

A simple way to find out where files installed by the package will go in the file system is to use the suspicious package QuickLook plugin. Note that install script in the package might still alter the filesystem in other ways.