By default, new organizations are configured to disallow the forking of private repositories.
If you allow forking of private repositories at the organization level, you can also configure the ability to fork a specific private repository. For more information, see "Managing the forking policy for your repository."
- In the top right corner of GitHub Enterprise Server, click your profile photo, then click Your profile.
- On the left side of your profile page, under "Organizations", click the icon for your organization.
- Under your organization name, click Settings.
- In the left sidebar, click Member privileges.
- Under "Repository forking", select Allow forking of private repositories or Allow forking of private and internal repositories.
- Click Save.