SEC_ERROR_UNKNOWN_ISSUER – 5 Ways to Fix This Error

Sometimes, when you’re trying to browse any website in Firefox, suddenly it will through an error. Error page conveys you that “Your connection is not secure”. In that case no need to be tense, it is the cause of error called SEC_ERROR_UNKNOWN_ISSUER. Shortly, we will let you know what is what and how to fix the Error.

What is SEC_ERROR_UNKNOWN_ISSUER?

It is an Error Code in Mozilla Firefox, which tells us “Your connection is not secure”. It means Firefox is unable to link up to a trusted Certificate Authority on the basis of information provided by the Website.

Why it occurs?

If you’re intended to make secure https connections, Firefox needs to verify that certificate presented by the website is valid or not.

If the certificate is not valid, you will get “Your connection is not secure” error page and click on the Advanced button, you can find the error code as ‘SEC_ERROR_UNKNOWN_ISSUER’.

You can find the Error Page as below.

What are the probable causes for this Error Code?

If you get this error on multiple individual HTTPs- sites, there must be something on your system or network is intercepting your connection. And injecting certificates in such a way that, Firefox cannot trust them.

The most common causes are

• Security software scanning encrypted connections
• Malware listening in
• Replacing the legitimate website certificates with their own.

How to Fix SEC_ERROR_UNKNOWN_ISSUER ?

After knowing what is this error? and why it occurs? Every one of us interested in finding what are the best ways to fix this issue? We will let you know the different ways to fix this error.

Sometimes, you will get this error because of mismatch in System date and a current date. If the System date is correct then you shall go for below-mentioned methods

Method 1 – Refreshing Firefox

• Firefox —> Options Menu (Which is on top right corner) —> Help Menu ( Question Mark) —> Troubleshooting Information —> Refresh Firefox(Right Upper Corner)
• Once You click Refresh Firefox, you will get the up-to-date Firefox with all latest updates.

Method 2 – Solving Anti-Virus Software Issues

Antivirus Programs like Kaspersky, Avast, Bitdefender, BullGuard intercepts the connections and injects their own certificates. We will let you know how to disable the interception of secure connections for the above antivirus products

Kaspersky

If you are using Kaspersky Antivirus product, here are the steps to secure connections

• Open the home page of Kaspersky Application
• Click on Settings on the bottom-left
• Click Additional and the Network
• If you’re using 2016 version of Kaspersky – Go to Encrypted connections scanning section and confirm Do not scan Encrypted connections option. If you are using 2015 version: uncheck the Scan Encrypted connection option. Restart the system for observing the changes

Avast

• Open the home page of your Avast Software.
• Go to Setting –> Active Protection –> and click Customize next to Web Shield.
• Just Untick the Enable HTTPS Scanning Setting and confirm this by clicking OK.

Bitdefender

• Open the homepage of Bitdefender
• For the 2016 version –> click on Modules
  •      2015 version –>click on Protection
• Go to Web Protection
• Toggle off the scan SSL Setting

Bullguard

In Bullguard security product you can disable the interception of secure connections on popular websites like Google, Yahoo, and Facebook.

• Go to home page of Bullguard application
• Click on  Antivirus settings –> Browsing
• Uncheck the Show safe results option for those websites which are showing an error message.

Method 3 – Changing the values of root certificates

• Open a new tab and type about:config in the address bar and press enter–>security page will display and it will ask you to I Accept the risk!, Click on the button promising to be careful or accepting the risk.
• After Click on accepting the risk, a list will display in Firefox. In the search box, type root and filter the list.
• Double click the security.enterprise_roots.enabled and change the value from false to true.
• Now you can go to your Firefox and refresh it to check whether you can browse any website.

Method 4 – Toggle ssl3 connections

• Open a new tab and type about:config in the address bar and press enter–>security page will display and it will ask you to I Accept the risk!, Click on the button promising to be careful or accepting the risk.

 

• After Click on accepting the risk, a list will display in Firefox. In the search box, type ssl3 and filter the list.
• Select security.ssl3.dhe_rsa_aes_128_sha && security.ssl3.dhe_rsa_aes_256_sha change value from true to false.

Method 5 – Delete Cert8.db for firefox

Sometimes some certificates in Firefox may cause to get this error, You just need to delete those certificate to browse any site without interruption

• Firefox —> Options Menu (Which is on top right corner) —> Help Menu ( Question Mark) —> Troubleshooting Information
• In Troubleshooting information window, you will find Application Basics. Double-click on Show Folder
• After Double-Click on Show Folder, one window will open. Search for Cert8.db file and delete it permanently. Before Deleting the file, close the Firefox.

Conclusion

In spite of many other methods to resolve Sec_Error_Connection, we strongly recommend you to use above listed methods. By considering system security, performance and memory they are the best ways to resolve the error. If you are getting error cause of antivirus software, use the best practices as mentioned above.

If you know any other best methods to resolve the error, please do mention in the comment box. We will dig and provide the more information to the other technology enthusiast. Hope that you guys will provide your valuable feedback and suggestions for the above content.