If you have the 'Mac App Store and identified (trusted) developers' option selected, then when you download an app without a Developer ID and try to open it, you'll get the following warning. 'App Name' can't be opened because it is from an unidentified developer. One of the security features of OS X 10.8 “Mountain Lion” is to only allow Apps from the “Mac App Store” or by an identified developer to run on your Mac. This brief tutorial will show you how to run those Apps anyway, or the disable the new “feature” entirely. As illustrated in the screenshot How to Open OS X Apps That Are “From An Unidentified Developer” Read More ». While the Mac is a little more open than iOS - the only way to get third party apps onto your iPhone and iPad is to download them from the iOS App Store - there are still a lot of hoops to jump. Updated November 26th, 2019. Sometimes you download a Mac app and it won’t open. You get a dialog box that says the app can’t be opened because it’s from “an unidentified developer” and your security settings won’t allow it.

One of the security features of OS X 10.8 “Mountain Lion” is to only allow Apps from the “Mac App Store” or by an identified developer to run on your Mac. This brief tutorial will show you how to run those Apps anyway, or the disable the new “feature” entirely.

Some Mac users say that they can't download programs from other website except Mac App Store, or they may can't be opened the download file. When they click on the download file, it says 'xxx can't be opened because it is from an unidentified developer'.For example.

Mac Can't Open App

1. As illustrated in the screenshot below, I tried to run the App SABnzbd+ but wasn’t “allowed” to by OS X – because it was created by an unidentified developer. Not helpful.
2. The “quick” and safer way to run the App is to locate it in your Applications folder, right-click (ctrl+click) the App, and select Open. This will run the App regardless as to who the developer may be.
3. If you would like to disable this new security feature so that you’re never “warned” or “stopped” from running programs that were created by unidentified developers, open your System Preferences from the Apple Menu, and select Security & Privacy.
4. Select the General tab, and click on the “lock” in the bottom left corner.
5. Enter your password when prompted.
6. In the section titled Allow applications downloaded from: – select Anywhere. You’ll immediately be presented with a ‘warning’ window telling you how you can open individual Apps without disabling this feature entirely (which would have been nice to know way back in step #1). Click Allow From Anywhere. You can exit out of the System Preferences now.
7. I don’t strongly advocate disabling this feature. The default setting is safer, and you can always right-click (ctrl+click) the App and select Open to run it when needed. It can be a pain if you use an Application Launcher like Quicksilver, but your Mac will be safer.

Apple’s App Store is a great place to download and install apps for your Mac OS but it isn’t the only place. You can download many apps from third-party developers which are quite useful for many people. However, Mac OS X implements some great security measures to prevent you from accidentally running malicious apps that might or might not damage your computer. But in some cases, it also prevents you from installing legitimate apps from running on your Macbook. We have two methods using which you can allow apps from unidentified developers on Mac OS X.

Mac Wonʻt Open App Unknown Developer Software

There are many third-party developers who develop apps for Mac OS but some of them are unidentified developers. Mac allows apps only from the App Store and some recognized developers. So, if you’re trying to install software from unknown developers, you’ll get the below error.

Apple has introduced a security feature called the Gatekeeper from OS X Mountain Lion. The Gatekeeper analyzes an app when you run it and determines whether it is authorized to run on your computer. If it fails to meet the requirements, the app won’t be allowed to run on your computer. So, below are the two workarounds to open apps from unidentified developers in Mac OS X Yosemite and above.

There are 2 ways you can allow apps from unidentified developers on Mac OS X and below, we’ll discuss both.

Method 1: Temporarily Run an App from Unidentified Developer

1. Open the location where you have placed the downloaded app/disk image file on your Mac.
   
2. Press and hold the Ctrl key while right-clicking on the app/file to open the drop-down menu.
   
3. Click on Open. Now, you’ll see a pop-up asking if you’d like to open this file. Press Open again to launch the file.
   

Method 2: Change the Gatekeeper Settings

This method will allow all the apps/files from unidentified developers to run on your Mac without limitation. However, it is not recommended for starters to use this method as you may run some malware from unrecognized sources which might harm your computer. So, proceed with this method only if you’re sure of what you’re doing.

1. Open System Preferences. To do this, either click on the System Preferences icon in the Dock or from Apple Menu > System Preferences.
   
2. Open the Security & Privacy settings by clicking Security & Privacy in the System Preferences window.
3. In the General tab, click the lock icon labeled Click the lock to make changes at the bottom of the window.
   
4. Now it may ask for your credentials to authenticate the action. So, provide your login credentials and click Unlock.
5. Under the section labeled Allow applications downloaded from:, select Anywhere.
6. You’ll get a prompt to confirm again. Click Allow From Anywhere to change the settings.
   
7. Close the settings window once you’re done.

That’s it. Now you can simply install apps/files from unidentified developers on your Mac. Let us know if you have any queries in the comments section.

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