
With the release of macOS Sierra, Apple has changed how it installs apps not downloaded from the App Store. Installing an application from an unidentified developer has become a little more difficult - additional actions are required from the user.

When trying to install an application downloaded from a non-official Mac App Store, the user will see a message like this on the screen:

or

Starting with macOS Sierra, Apple changed the security settings to work with downloaded programs. You can check them by opening the "Protection and Security" → "General" section in the "System Preferences" application.
As it was before…
To get a complete picture of the changes, let's compare the settings in macOS Sierra and older software versions. In earlier editions, the Allow Programs Loaded From tab included three options:
- Mac App Store - Mac runs apps downloaded exclusively from the Mac App Store.
- Mac App Store and Installed Developers - The system cannot open a new app that is not in the list of installed developers.
- "Any source" - this option allows you to open all programs received from any source.

How to install apps not downloaded from the Mac App Store
Method 1. Confirming each developer manually in System Preferences
Starting with macOS Sierra, the Any Source option has disappeared. Now, Mac owners who have updated to the new version of the operating system will no longer be able to use this feature to open downloaded applications.

However, there are at least two ways to launch programs not obtained from the Mac App Store, but from other sources.
1. After moving the downloaded application to the Applications folder, launch it. A warning of the form will be displayed on the screen:

or

Click Cancel or OK. This will take you back to the Finder file manager.
2. Then go to the path: "System settings" → "Protection and security".

3. In the "General" tab in the "Allow the use of programs downloaded from" section, click on the "Confirm login" button (you may need to enter the Administrator password).

A new alert will appear, but an Open button will appear, click it to launch the application.

In case of loading another application from the same developer, the system will check the list and open the program.
Method 2. Force permission to install applications on Mac from any source using a command in the Terminal
To disable developer verification when installing applications, run the following command in the Terminal program (you will need to enter the administrator password):
sudo spctl --master-disable
Press Enter on your keyboard.

This command will return the "Any source" item along the path "System settings" → "Security and safety".

To return to the "default" state, use this command:
sudo spctl --master-enable
See also:
- How to remove a USB flash drive, removable disk (drive), etc. on macOS (7 ways).
- Everything about tags in the Finder on Mac.
- How to change the speed of hiding and showing the Dock in macOS.