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DLG_FLAGS_INVALID_CA error explained

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What is SSL (Secure Sockets Layer)? How does it protect a website?

Sometimes when you hit up a site, you might see an error pop up something along the lines of the title of this article. This error may or may not be accompanied by other issues. It’s a confusing thing to come across for most people.

The DLG_FLAGS_INVALID_CA error or a few other errors that indicate roughly the same thing, such as DLG_FLAGS_SEC_CERT_CN_INVALID or DLG_FLAGS_SEC_CERT_DATE_INVALID indicate an error with the security certificate, otherwise known as the SSL certificate of the website.

In this article, we will talk about these errors, what causes them and what you can do to solve them potentially.

Also read: What is the About:Blank page? Why is it on your browser?

What are these errors?

Aforementioned, these errors pop up when there’s an issue with the site’s security certificate. These certificates are issued to secure sites that handle your data safely and securely. If a site doesn’t have this certificate, it could indicate fishy business.

More often than not, the webmaster or the site admin/developer hasn’t either.

  • Installed an SSL security certificate, yet
  • Not correctly installed their security certificate
  • Not renewed their security certificates 
DLG_FLAGS_INVALID_CA error explained | Candid.Technology

The plaintext error accompanied by these errors often reads, “Attackers might be trying to steal your information from (for example, passwords, messages, or credit cards).” or something along those lines.

After seeing this, most people would, by default, close the site and not revisit it, but it’s not as bad as it seems. 

Also read: How do browsers work? The science behind rendering a webpage

What to do if you see this error?

As you can see in the screenshot above, you have two ways out of this

  • Close the website
  • Click the Advanced button to let you access the site anyway.
DLG_FLAGS_INVALID_CA error explained | Candid.Technology

Now depending on what you want to do on the site, it’s perfectly fine to go ahead and visit it. If you’re looking to browse or look something up, you’re all good to go.

We would, however, advise against filling out any forms or giving away any data to said sites for as long as you see these errors. Once the site is restored and the error is resolved, any data you enter is guaranteed to be safe by the certificate provider. 

Also read: How to get a free SSL certificate for your website? How is it different from paid SSL?

How to fix this issue?

More often than not, this is an issue on the backend and is the site administrator’s responsibility to resolve. However, there can possibly be a few things wrong on your end too.

Here are a few things that you can try:

  • Clear your browser’s cache(here’s how to do it on Chrome and on Edge)
  • Try using another browser.
  • Make sure your system date and time is right.

While some guides suggest turning off the Warn About the Certificate Address Mismatch setting off in order to access such sites, we strongly recommend against it as it can put your entire web browsing experience at risk.

If all this is good on your end, chances are the server admin hasn’t renewed or installed the certificate correctly. If you can contact them, send them a message highlighting an issue.

Also read: How to clear browsing history and cache in Edge 2020 (Chromium)?


Yadullah Abidi

Yadullah is a Computer Science graduate who writes/edits/shoots/codes all things cybersecurity, gaming, and tech hardware. When he's not, he streams himself racing virtual cars. He's been writing and reporting on tech and cybersecurity with websites like Candid.Technology and MakeUseOf since 2018. You can contact him here: [email protected].