How to fix an unidentified developer problem in OS X Mountain Lion

Solution to open app from unidentified developer

After upgraded to OS X Mountain Lion, the DAA Converter application was not able to open. It indicated ” New App” can’t be opened because it is from an unidentified developer.

In brief, it is a new feature called “Gatekeeper”. Primary, this features disallow users to open apps that are downloaded without the “identified and trusted developer”. To solve this problem, there is two simple methods to bypass Gatekeeper.

First Solution

Do not double-click to open the app. What you need to do is Ctrl+click or right click on the app and select Open.

Next, the popup display the same messages but this time with the open button.

Click Open, Done!

Second Solution

Go to System Preferences and Click on the Privacy & Security icon in the top row.
 

Under the General tab – Allow application , Select Anywhere instead of Mac App Store and identified developers.

Remark: The purpose of Gatekeeper is to prevent any malware or malicious apps. Disable at your own risk.