I keep getting the same error when trying to install Arduino on my Mac. I'm running El Capitan 10.11.2. The file won't unzip. The error says it is unable to expand. Error 2 - no such file or directory. Anyone else have this problem? I've downloaded the file several times and gotten the same message.
You should probably update to 10.11.5 when you get a chance.
With 10.11.5 I just downloaded https://www.arduino.cc/download_handler.php?f=/arduino-1.6.9-macosx.zip and double-clicked on the file in my Downloads folder. It unzipped without error.
Perhaps you need a copy of Stuffit Expander Mac.