Maverick - causing problems
Why do I get messages saying that it "cannot be opened because its from an unidentified delevoper"?
iMac (27-inch Late 2009), Mac OS X (10.6.8)
That's caused by Gatekeeper > http://support.apple.com/kb/HT5290?viewlocale=en_US&locale=en_US
To open the app you are trying to open, right-click it and select Open.
Another thing you can try is to go to System Preferences > Security & Privacy > General, press the padlock at the bottom right corner of the System Preferences window, and select "Anywhere" under "Allow applications downloaded from"