A couple of weeks ago, I was troubleshooting an app that wouldn’t open on my Mac, and I tried to download a version of it from the developer’s website to replace it. I downloaded it with no problem, but when I tried to open the .dmg, I got the message: “[App I tried to open] can’t be opened because it is from an unidentified developer.”

Well, that’s a bummer. I figured there must be a way around this, and there is. (I’m running 10.9 on my home computer, by the way, but this should be applicable from at least 10.8 on.)

  1. Open System Preferences
  2. Click on Security & Privacy
  3. Select General
  4. Click the lock to make changes (if applicable; you’ll need to type an admin’s username and password)
  5. Under “Allow applications downloaded from:” select Anywhere

That option is not checked by default, so by changing it, you’ll be able to open apps you’ve downloaded going forward. Just make sure they’re from a trusted source!