Some websites show ERR_SSL_PROTOCOL_ERROR or SSL_ERROR_ACCESS_DENIED_ALERT in the browser

Issue:

When a user tries to access some websites with their internet browser, they are shown the following error depending on the browser in use:

• Google Chrome and Microsoft Edge: "The connection for this site is not secure – <website address> sent an invalid response – ERR_SSL_PROTOCOL_ERROR
• Firefox: "Secure Connection Failed – The page you are trying to view cannot be shown because the authenticity of the received data could not be verified – Error code: SSL_ERROR_ACCESS_DENIED_ALERT" 

Why are these errors shown only on specific sites and how can we fix these errors from appearing?  

Resolution:

This error is shown because the Browsing Protection feature has blocked the website and the Browsing Protection by WithSecure browser extension / add-on is either not installed or activated in the browser. The extension / add-on is required to be able to show the Browsing Protection block page on HTTPS websites. On HTTP sites the block page can be shown even when the extension / add-on is not installed or active in the browser. 

A website can be blocked for example if:

• Website is rated as harmful or suspicious by Browsing Protection
• Website category has been blocked by the Web Content Control feature
• Connection Control is active and the website is not rated as safe for banking

You need to make sure that the Browsing Protection by WithSecure browser extension / add-on is installed and active in your browser. 

How to install the extension / add-on: 

1. Right-click the Elements Agent or Client Security icon in Windows the system tray
2. Click Open settings 
3. Go to the Browser extensions settings page
4. Follow the instructions to install the browser extension