Hi,
I am trying to get installer online but it says “Installer” can’t be opened because it was not downloaded from the Mac App Store. I hope you one of your expert can fix this issue. Looking forward the applicable solution. Thanks!
“Installer” can’t be opened because it was not downloaded from the Mac App Store.
Your security preferences allow installation of only apps from the Mac App Store.
This error happens because OS X only allows installation of apps downloaded from the Mac App Store. This means, when you download a program on OS X from a different website not from the Mac App Store and installed it, the operating system will not allow you to install it. OS X restricts installation of unsigned apps.
Apple wants users to use apps downloaded only from the Mac App Store. But there’s a workaround on this. You just need to make OS X allow you to install unsigned apps. To do this, click on the Apple menu and select System Preferences.
In System Preferences, select Security & Privacy.
In Security & Privacy, under “Allow applications downloaded from”, select Anywhere. When you are prompted, click Allow From Anywhere.
After this, run the installer and install the app. In case you are prompted, just click Open. When the installation completes, go back to Security & Privacy and select “Mac App Store and identified developers”. And that’s it. Just repeat the same steps whenever you want to install unsigned apps.
