Fix third Party app Can’t be opened because it is from an unidentified developer Error

Mac has been known for its best security measure because Apple has built it in a way that it protects you from all the possible Malware, Spyware and Virus attack. Starting from Mac OS X Lion, Ver 10.7, Apple introduced an amazing feature in OS X which is known as GateKeeper. Yes, just like a gatekeeper which works as a watchman and keep an eye on everone who tries to enter your house. Gatekeeper also make sure that only the authoritative and good software can be installed on your Mac. If anything not identified by Apple tries to get into your Mac or want to silently install on your machine, will be blocked immediately by GateKeeper. When such software is blocked a pop up message saying “App Can’t be opened because it is from an unidentified developer” will be displayed. In this post we will learn how to bypass this message for some of the third parties app that you want to install on your Mac. After reading this post you can easily fix and open third-party apps from unidentified developers in macOS. In order to understand and fix this problem, you must know what is GateKeeper?

third Party app Can't be opened because it is from an unidentified developer
Third Party app Can’t be opened because it is from an unidentified developer Error

What is GateKeeper?

GateKeeper is the security feature of the Mac OS X system that block software from an unidentified developer to run on your Mac. If checks if the software code is signed by Apple and verifies the download download before it is allowed to run on Mac. It thus reduces the chances of malware or virus attack. Most of the viruses and Malware software are actually injected with innocent third party app and redistributed through free download platform other than the App store. This feature was first introduced as command line utility named spctl in OS X Lion version 10.7.3 and then later included with most of 1.7.5 as a GUI option and all the OS X later got this GateKeeper in graphical User interface.

This GateKeeper thing will never stop any apps from the app store because thay have already been tested and passed the quality check by Apple. In mewer macOS version, by default, any apps downloaded from internet and not from the app store will be blocked to open. Some time the apps that are not downloaded from the app store but are from and identified developer like Microsoft or Oracle will be installed without any error or warning. And sometimes even the software from Microsoft and Oracle will be blocked to open saying ” The app can not be opened because it was not downloaded from the App Store”. This new security features is just to make sure the automatically installation of harmful software are blocked. Soit does not mean that you can not download app outside the app store or apps from n unidentified developers. All this message is controlled by GateKeeper. It basically has following three options to choose from.

  1. Mac App Store
  2. Mac App Store and identified developers
  3. Anywhere

You can either set one of the above mentioned settings for permanently or temporarily bypass the GateKeeper and allow the third party app from unidentified developer or outside the app store to open. Also please note blocking a software to open does not necessarily means that the software is harmful rather it means the software has not obtained a valid signature from Apple. For more information you can also visit apple support page.

Fixing Mac Unidentified Developer App Installation issue:

Fixing error App Can’t be opened because it is from an unidentified developer

Following are the instructions that you need to follow if you want to allow thord party app from uidentified developer to open and run. We will also cover the error message “App can not be opened because it was not

Temporarily Allow the third app to open

This is probably the most easiest way for everyone, since it does not change the security settings but allow only the same app to open.

    1. Control click or right click the downloaded file and select “Open” from the context menu.
Allow Application from unidentified developer temporarily
Allow Application from unidentified developer temporarily
  1. A confirmation dialog box opens asking, “third part app name” is from an unidentified developer. Are you sure you want to open this.
  2. Click Open or Launch the app anyway whichever you see as per the version od OS X.

Now the app will be opened and you can install it. You have to do this everytime you want to open such apps. In case you want allow third party apps from unidentified developers permanently then follow the next steps. This second issue will eliminate the error message app Can’t be opened because it is from an unidentified developer forever.

Disable GateKeeper’s Unidentified App Developer Error Message Permanently

This settings will allow all the third party apps from any developer to launch and install on your Mac without showing any warning. Please choose this option carefully and only when you are sure what you are doing.

  1. Click Apple icon and select System Preferences.
  2. Allow apps from unidentified developer permanently
    Allow apps from unidentified developer permanently

    Choose “Security & Privacy” and then select “General” tab.

  3. Click the golden lock icon at the bottom left corner of the window.
  4. Type the administrator password to confirm opening the security lock to make changes in setting. If you do not remember your admin password. You can follow the steps in post how to reset Mac administrato password.
  5. Once the security lock is opened, Select “Anywhere” under “Allow applications downloaded from:”.
  6. Accept the confirmation message that yes “Allow applications downloaded from anywhere”.
  7. Now close the box and system preferences window. Try to open the downloaded app again and it should work fine.

I hope this will fix error message App Can’t be opened because it is from an unidentified developer on your Mac. If you are still unable to do this and can not fix this problem you can contact us at Apple Mac tech support phone number for a free consultation and diagnosis. Thanks for reading this troubleshooting article. Feel free to chat with one of our technicians available 24/7 for your help.

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