5 Ways to Fix the “SSL_ERROR_NO_CYPHER_OVERLAP” on Firefox


Have you ever encountered the ssl_error_no_cypher_overlap error when trying to access a website on Mozilla Firefox? There are various methods that you can use to solve the issue.

What is ssl_error_no_cypher_overlap?

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The ssl_error_no_cypher_overlap error only occurs on Mozilla Firefox. However, it shouldn’t be a cause for alarm. There are methods you can use to solve the issue.

This prompt often occurs when the SSL certificate verification is invalid when trying to access a certain website. In this, Firefox is unable to obtain security data from the target website. The most likely reason is that the SSL certificates of the target websites have expired. The SSL secure connections are essential.

1: Update Mozilla Firefox browser

To solve the issue, you can first try to update your Mozilla Firefox browser.

Step 1: Open your Mozilla Firefox browser.

Step 2: Click on the menu icon in the top right corner. It is displayed as three horizontal lines.

Step 3: On the menu, scroll down and click on help.

scroll down and click on help

Step 4: On the Help menu, click on “About Firefox.”

About Firefox

Step 5: The “About Mozilla Firefox” window will open. Furthermore, it will automatically check to see whether your Firefox is up-to-date. If it is an outdated version, ensure to update it.

About Mozilla Firefox window will open

2: Uninstall and install Mozilla Firefox

Alternatively, if that doesn’t work, uninstall then install Mozilla Firefox.

Step 1: Click on Windows + S button and search for the control panel in the search bar.

Click on Windows

Step 2: Click “program and features.”

program and features

Step 3: While on programs and features, navigate to Mozilla Firefox, right-click, then uninstall.

navigate to Mozilla Firefox

Step 4: Once done, go to Mozilla Firefox official page, download Mozilla again, and install. Check whether the error still appears.

3: Reset TLS encryption protocol and ssl3

TLS and SSL browser encryption is necessary while browsing on the internet. Without the SSL and TLS, data gets sent as plain text, and malicious parties can easily alter with this data. However, with the protection, the data remains secure during transportation.

Step 1: Open Mozilla Firefox browser, input about: config on the Mozilla Firefox address bar.

Mozilla Firefox about config

Step 2: On the next webpage, click on “accept the risk and continue.” Then click “show all.”

accept the risk and continue

Step 3: On the search bar, search for TLS. The page will display a couple of results.

TLS for mozilla firefox

Step 4: Look for any values that look bold, set them to default settings. When bold, it means that there are recent changes that have been made to the values.

Step 5: The next thing is to change some two ssl3 values. Search again for ssl3, then search for these two values:


security ssl3 128 value


security ssl3 256 value

Step 6: Make sure that the values ​​of these two items are false.

Try to check whether the website has started working normally. If not, you can return the default settings.

4: Check security protocols and browser configuration files

The other method is to check the security protocols and browser configuration files.

Step 1: Search for about: config in the Mozilla Firefox address bar.

Mozilla Firefox about config

Step 2: Click on accept the risk and continue.

accept the risk and continue

Step 3: Search for TLS, and on the result page, search for the two values and click on the pencil icon, and change to 0.

security. tls.version.fallback – limit
  from 4 to 0

security tls version fallback

  from 3 to 0

security tls version min

Step 4: After you are done, input about: preferences in the address bar, then click the “Privacy and Security” option. These privacy settings are critical.

about preferences

Step 5: Scroll down and turn off “Block dangerous and fraudulent content”

Block dangerous and fraudulent content

Step 6: Then, try to access the specific website that you want to try. If it doesn’t work, change the tls values to how they were before.

security.tls.version.fallback – limit
  from 0 to 4

from 0 to 3

That’s it!

5: Use another browser

troubleshooting the network problem with different browser.

If that doesn’t work, try to switch to browsers such as Google Chrome, Microsoft Edge, Opera Mini, or Waterfox. Try to access the specific website and see whether it works.

It might be the issue and not the browser. Check whether the problem is resolved. This will help to verify connections to sites.

Browse Websites on Mozilla Firefox fast

Browse Websites on Mozilla Firefox fast

If you ever encounter that issue, you can use any of these methods to solve the problem. However, try to be sure of your tracks to return the settings to the default values.

Also, try to check whether there is an issue on your local device because that can cause some issues. Furthermore, be wary of the kind of software you download from the internet constantly. This will prevent the error message from appearing often.

FAQ – Frequently Asked Questions

1. What is SSL?

SSL stands for Secure Sockets Layer.  It performs different functions such as identity authentication, keeping data confidential, and ensuring data integrity. This ensures full security while you are browsing on the internet.

2. Will I encounter this issue on other browsers?

Similar error codes appear in other browsers. For example, in Google Chrome, you can get ERR_SSL_VERSION_OR_CIPHER_MISMATCH.

However, there are different solutions for solving such issues on different browsers.

3. What is TLS?

It is a protocol that provides end-to-end communication security over networks. It is mainly used for internet communication and online transactions.

It helps to prevent eavesdropping, tampering, or message forgery. TLS is used for web browsers, instant messaging, email, and voice-over IP.

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