I normally create some Mac apps on one computer and transfer them to another computer for testing. Several months ago I ran into the "gateway problem" where the Mac blocks unidentified apps and solved it by going to the security & privacy and changing my settings to allow apps downloaded from "anywhere". Now all of a sudden apps that I transfer for testing will not run on the test computer. When I double-click on the app there is a brief flash but nothing happens. I can click on the same app file that I transferred to the test computer four months ago and it has no problem opening.
I'm running OSX 10.9.2.