Security Certificate Update Error

On May 30, 2020, Sectigo, a major provider of SSL certificates on the Internet, retired its old root security certificate for older operating systems and software. This did not impact any users on operating systems released in the past 4 years, but those on Mac computers running macOS 10.11.6 (El Capitan) and older will receive certificate errors. Since El Capitan's support life ended in 2018, users with this issue should prioritize upgrading immediately, as they have not been receiving security updates for MacOS for three years.

You can refer to this guide from Apple to find out which macOS your Mac is running.

Security certificates verify a website’s authenticity to a browser. Chrome and Safari rely on the operating system to be able to do this check, and with macOS 10.11.6, they cannot verify the legitimacy of Emerson sites and will block them from opening. Firefox stores its own certificates and does not rely on the operating system, and as of release 36, has had the necessary certificate and is therefore not affected.

Chrome users, for instance, will see:


The certificate error as displayed in Google Chrome 

You may encounter a similar error message when trying to connect to the VPN via GlobalProtect.


The certificate error as displayed by GlobalProtect

If you have encountered these errors and need immediate access to an Emerson website, try using Firefox. If you are on a personal computer without Firefox installed, you can install it directly from the Firefox website.

The best solution (especially if you are trying to user GlobalProtect) is to update your operating system. The latest version that Emerson College supports is MacOS Mojave (10.14).

How to Upgrade your Operating System:

Before upgrading, please back up all important data on your computer.

For more information on backing up your data, please visit our guide on Backing Up Data at Emerson College.

If you are using a personal computer:

  1. You can download the Mojave installer directly from the the App Store
  2. Once the installer downloads, click on it to start the upgrade process.

If you are using an Emerson-owned computer:

You will need to update to High Sierra (10.13) before moving to Mojave.

  1. You can download the High Sierra installer from the App Store.
  2. Once the download finishes, open the installer to start the update process. 
  3. Once the installation is complete, you can update to Mojave via the Emerson IT Self Service application. 

If you have any questions about these steps, please submit a ticket to and the Help Desk will help get your computer updated.



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