In order to properly access the Secure Message center, your browser must have TLS 1.0 (or higher) enabled.
To enable these settings in Internet Explorer:
1) Select "Tools" > "Internet Options".
NOTE: Depending on your IE settings, the "Tools" menu may be a gear icon in the upper right hand corner.
2) Go to the "Advanced" tab.
3) Scroll down to the "Security" section.
4) Locate and check "Use TLS 1.0".
If you browser has additional TLS options, such as TLS 1.1 and TLS 1.2, these should also be selected.
5) Then, press the "OK" button.
You may need to close and reopen all open browsers in order for these new settings to take effect.