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How To Avoid TLS Errors When Logging Into EP Controllers

Overview​

Modern browsers often enforce TLS protocols that are not supported by older Mercury EP Controllers.  Instructions here can assist you when you need to use a browser to log in to the EP controller web-UI.

Browser Use​

Avoid Chrome/Edge browser, instead use Firefox browser

Enable older TLS options in browser​

NOTE: The changes below should only be made temporarily for the purpose to logging into the controller.  Once that work is completed it is strongly recommended that you revert these changes to the original settings.  Leaving the settings below will weaken the security of Firefox browser.

  1. In Firefox URL/address bar type in "about:config" and press Enter
  2. Type "tls.version" in the search box to find the settings we want to change
  3. Double-click the "security.tls.version.enable-deprecated" to change the setting to "True"
  4. Click the edit button for "security.tls.version.max" and modify the setting from "4" to "2"

After making these changes, restart the Firefox browser and pull up the EP controller UI via the IP address.  You will still be warned that the site is a security risk and will have to select the options to continue anyway.

Please note that we have seen that it may take a few attempts to get the controller UI to load/bypass TLS errors.  If you still have a TLS error when trying to load the UI, refresh/reload the page a few times.