This site is not secure: How to fix this browser error

by Ivan Jenic
Ivan Jenic
Ivan Jenic
Troubleshooting Expert
Passionate about all elements related to Windows and combined with his innate curiosity, Ivan has delved deep into understanding this operating system, with a specialization in drivers and... read more
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  • If you keep getting the error message This site is not secure, some certificates might be missing.
  • When you're blocked from a website with a Your connection to this site is not secure pop-up, install certificates first.
  • When a browser message shows not secure, a quick website fix is to clear cookies and cache. 
  • Changing the Certificate address mismatch option is another easy solution to try.
fix This site is not secure

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Due to security reasons, whenever the safety shield of a blocked website is compromised you may get the message The site is not secure or DLG_FLAGS_SEC_CERT_CN_INVALID.

It comes up on any version of Windows, but Windows 10 users are most frequently complaining about this bug currently.

This error may also occur due to missing a trusted root certificate or because the website contains malicious ads, codes, and links.

However, you may proceed by clicking on the Go on to the website (Not Recommended) button if you have visited the website before and your web browser did not block it.

In order to solve this intimidating problem, we have compiled universal solutions to fix it in various web browsers such as Microsoft Edge, Google Chrome, Mozilla Firefox, Opera, and Internet Explorer.

Ignoring this warning may expose your PC to malware. Use the workarounds listed below at your own risk.

Quick tip:

Before continuing, if you’re looking for a privacy-compliant browser that’s less prone to glitches, we recommend downloading Opera.

Besides the built-in ad-blocker, it also comes with an unlimited VPN service that offers you the ability to choose from 3 different locations.

The VPN will help you hide your IP address while online, and also keep trackers at bay.

The browser is also extremely fast and reliable, so the websites will not only load error-free but will also load extremely fast.



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What can I do to correct This website is not secure pop-up?

1. Manually install missing certificates

this website is not secure
  1. When the message appears, click on the Continue to this website (not recommended) option at the very bottom of it.
  2. Click on the More Information for the Certificate Error option next to the red Address Bar.
  3. Then, click View Certificates on the information window.
  4. Select Install Certificate and follow the on-screen instructions.
  5. Finally, click Yes on the dialog to proceed.

NOTE: Manual installation of certificates is not recommended on strange websites or websites with a low reputation. Furthermore, manually installing the certificate should fix the This site is not secure error pop-up.

2. Clear web browser cache, data, logs, and bookmarks

The fastest way to clear browsing data in any web browser is via the Ctrl+Shift+Del keyboard shortcut.

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Also, you can use a good cookie cleaner utility program to clear all your browsing history in one click.

Manually deleting cookies and cache is rather simple, no matter the browser you have. We’re detailing the process below.


  1. Launch the Opera browser
  2. Go to the Settings menu
  3. Proceed to the Clear browsing data menu
  4. Click on the detailed option to tick the delete the entire cache option.
  5. Click on the Clear data option to clear the entire browsing data.

Note: For detailed instructions on how to clear the cache in Opera, check out their official documentation.

Google Chrome

  1. From the Menu button in the upper-right corner of the Chrome window, choose More Tools, then Clear browsing data.
  2. Using the Clear the following items menu you can select the beginning of time to delete all the cached information using the drop-down menu.
  3. From there, you can select Cached images and files.
  4. Select the Clear browsing data button, and Chrome will clear your cache.

Internet Explorer 11

this site is not secure
  1. On the right-hand side of the browser, click on the Tools (gear) icon.
  2. Select Safety, then Delete browsing history.
  3. Uncheck all options except the one labeled Temporary Internet files and website files.
  4. Then, click the Delete button at the bottom of the window.
  5. The Delete browsing history window will disappear and your mouse icon might go busy for a while.

Note: For IE lower versions, if the Menu bar is enabled, click the Tools menu and then delete browsing history. Keyboard shortcut Ctrl-Shift-Del can be used as well to clear browser cache.

Microsoft Edge

  1. While in Microsoft Edge, click the History icon this site is not secure.
  2. Go to the three-dot menu and select Clear browsing data.
  3. Check the data that is going to be deleted.
  4. Then, click the Clear now button.
    • The message All Clear! will appear after the data has been erased.

Mozilla Firefox

  1. In Firefox, click the Menu button (the hamburger icon) and then select Options.
  2. Click on the Privacy tab on the left.
  3. Then, in the History area, click the clear your recent history link.
  4. In the Clear Recent History window that appears, set the Time range to clear: to Everything.this site is not secure
  5. Uncheck everything in the list except for Cache.
  6. Proceed by clicking on the Clear Now button.

If the pop-up message about your website not being secure still appears after clearing browsing data, proceed with the next step.

3. Disable the Certificate address mismatch option

  1. Select the start button and go to Control Panel.
  2. Then Open Internet Options and click the Advanced tab at the top.This website is not secure
  3. Scroll down to the Security section.This website is not secure
  4. Identify the Warn about certificate address mismatch option.
  5. If the box right beside it is checked with a tick, you can unmark it to disable the option.This website is not secure
  6. Click Apply and OK to save the changes and close everything.

If the error This site is not secure DLG_FLAGS_SEC_CERT_CN_INVALID still persists on the website, it is advisable that you do not attempt to visit the website.

You can also contact the site administrators and ask them to look into this issue. They may check the website certificate and fix the error from their end.

If you’ve solved this error using other methods, feel free to comment below.

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