If you are trying to launch an application, which is not installed from App Store and the developer of the application is unidentified, then you may get an alert saying “[App name] can’t be opened because it is from an unidentified developer”. This security feature in Mac OS X is called GateKeeper, which by default blocks all the applications which are not from a verified source or from App Store.

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. First off, realize that Apple is doing this to help you avoid getting malware or spyware on your Mac computer. So far — knock on a convenient piece of wood — Macs have been far, far less susceptible to viruses and other bad software injected from Web sites, scam emails or similar, and one big reason for this is the vigilance of the operating system itself.

Fix “can’t be open because it is from an unidentified developer” for a particular application without altering security settings

If you want to add exception for a particular application without changing GateKeeper’s security settings, follow the steps below.

1. Here we have tried to launch “Open Office” and we got below error.
“OpenOffice” can’t be opened because it is from an unidentified developer

Open App From Unidentified Developer Mac High Sierra

2. To fix this, navigate to System Preferences > Security & Privacy.

Allow Apps From Unidentified Developers

3. There you can see below message “OpenOffice” was blocked from opening because it is not from an identified developer. Click on “Open Anyway” button, followed by “Open” in pop up. That’s it.

Now on you will able to launch this particular application (Here it’s OpenOffice) without any issue. Mac OS X will remember this exception for this particular application. But as default security settings of GateKeeper has not been altered, you will have to perform the same steps again if you get this issue for another application with unidentified developer.

You can also do the same by control-clicking (right click) on the particular application logo and then select “Open” option followed by again “Open” option to launch it anyway.

Permanent fix for all applications from unidentified developer

Sierra

Mac Cannot Be Opened Unidentified Developer

For doing this you have to alter security settings in your Mac OS X, which is not a good idea as it will make your Mac less secure. Instead of doing this it’s alway recommended to allow individual applications as stated above. For permanent fix for all applications from unidentified developer follow the steps below:

1. Go to System Preferences > Security & Privacy. Click the lock to make changes and enter your account password to verify.

2. Now set the radio button to Anywhere followed by Allow from Anywhere. This settings will be reset automatically if you don’t use this feature for 30 days.

Universal Problem Solutions

  1. Ifprompted:'xxx.app is damaged and cannot be opened. You should move it to the Trash' , It'snot that the apps you download is damaged, but the security settings of the Mac system. See solutions:Mac apps that cannot be opened orfiles are damaged
  2. Ifprompted:'Unable to confirm the identity of the developer, unable to open', It's not thatthe apps you download is damaged, but the security settings of the Mac system. See solutinons:Open the application of anunidentified developer
  3. Unified password for opening DMG and zip on this site: minorpatch.com
  4. Regarding the activation method, most articles have made different activationinstructions for differentversions.However, in the end, the actual situation in the dmg package shall prevail. If there is only a single .app or.pkg file,