The application “SomeApp.app” can’t be opened

Problem: after downloading an application in OS X Yosemite (10.10.x) trying to open the application (either from the command-line or by double-clicking the application) produces a dialog saying "The application “SomeApp.app” can’t be opened."

Note that this differs from the "SomeApp can't be opened because it was not downloaded from the Mac App Store" or "SomeApp can’t be opened because it is from an unidentified developer” message that is the result of Gatekeeper settings.

Solution 1:

After extensive trial-and-error, and a lot of fruitless Googling, I found the solution required modifying the executable status of the "inner" application file. This line: chmod +x SomeApp.app/Contents/MacOS/*

Fixed the problem in all cases that I observed. The +x flags a file as executable, and the only file in the /Contents/MacOS/ directory is a binary representing the actual file that should be executed when you double-click the application (a .app file is really just a folder).

Hope this helps someone else!

Solution 2:

1. in the Finder, locate the app (in the Applications folder, most likely)
2. Press the Control-key and click the app icon
3. Choose Open from the contextual menu

As in App Cannot Be Opened (even though that describes a workaround for the Gatekeeper app, it works for the scenario in the question as well)