Enabling this setting blocks external extensions (an extension that is not installed from the Chrome Web Store) from being installed. The recommended state for this setting is: Enabled (1) Rationale: Allowing users to install extensions from other locations (not the Chrome Web Store) can lead to malicious extensions being installed. Impact: User will only be allowed to install extension for the Chrome web store.
Solution
To establish the recommended configuration via Group Policy, set the following UI path to Enabled: Computer Configuration\Polices\Administrative Templates\Google\Google Chrome\Extensions\Blocks external extensions from being installed Default Value: Unset (Same as Disabled, but user can change)