How to fix “App can’t be opened because it is from an unidentified developer” for Mountain Lion and later

Since OS X Mountain Lion, default Mac users won’t be able to run an app from an unauthenticated developer by Apple, you’ll often get the message “[App name] can’t be opened because it is from an unidentified developer” when starting an application. The following article will guide you thoroughly to solve this problem.

This is actually one of the new features added to Mountain Lion, called GateKeeper, but it’s not a feature that doesn’t let you run an app from an unauthenticated developer, you just Temporarily block GateKeeper from checking this application or turn it off completely.

If you install macOS Sierra, see the instructions below:

Completely disabling GateKeeper may cause your computer to be troubled by software from third parties of unknown origin.

Completely disable GateKeeper’s developer censorship

This method is recommended for users who have a lot of experience and know which applications to trust or not.

To do this, follow these steps:

1- Open System Preferences.

2- Find and Click on Security & Privacy.


3- In the General Tab click on the padlock icon and enter the password.


4- In the “Allow appliations downloaded from:” >>>> Click chọn “Anywhere” and choose Allow From Any Where


5. Done

Only do it once, then you can install external applications without errors. However, be careful of the source of the application and make sure your application is trustworthy before installing. Applications downloaded at are all censored before uploading, so you can install them without worrying about system damage.

Wish you all success –


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