Please ensure all machines used for access are using the latest version of Google Chrome.
If you still receive an error message regarding certificates, please refer to the following instructions below to clear any stored security certificates on your machines.
To clear the SSL state in Chrome, follow these steps:
Click the Google Chrome - Settings icon (Settings) icon, and then click Settings.
Click Show advanced settings.
Under Network, click Change proxy settings. The Internet Properties dialog box appears.
Click the Content tab.
Click Clear SSL state, and then click OK.
Please also ensure your computer's time, date, and timezone are set.