Google to ban the external source extension to the chrome by the january of the next year. Windows users are allowed or able to install extension to chrome only through the official store. This ban is due to the security concern of the chrome users.
Google claims on its blog that the current security concern isn't enough for the chrome users for windows. When they install the extensions from the external source and the bad actors had figured out how to bypass it. The external source extensions had changed the new tab page in the chrome for the windows users.
The google ban on the external source extension will affect the stable and beta version users of the chrome in windows. Developers version of the chrome will remain unchanged. Google ask the website developers and the the business persons to migrate their extension to the google chrome store. Malicious extensions are strictly prohibited from the chrome store.
Web Developers and the business persons can use inline install and the enterprise policy to their extensions. This change might affect the security software providers who provide extension from external source in their update or in the installation. In such case google encourage the security developers to host the extensions in the store and hidden from the search.