How to Fix the “SSL_ERROR_NO_CYPHER_OVERLAP” Error: 5 Easy Fixes

The SSL_ERROR_NO_CYPHER_OVERLAP error occurs only in Firefox, unlike other browser issues.

A similar but somewhat different version is available in Google Chrome, with the warning “ERR_SSL_VERSION_OR_CIPHER_MISMATCH“.

In a word, this error occurs when Firefox is unable to receive security data from a website that you are attempting to visit.

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If you see this error message, it means your browser was unable to securely communicate with the server. It’s worth noting that SSL is nearly identical to Transport Layer Security (TLS), which will be discussed later.

As previously stated, this error code happens when the server fails to provide suitable security mechanisms or protocols in response to the browser’s request, resulting in the web page failing to load. There are, however, several more explanations, such as:

  • Firefox has not been updated to the most recent version, which causes problems when accessing the web.
  • The web browser has SSL3 turned off. TLS can also be disabled, which results in an error message.
  • Because RC4 support has been removed from Firefox, if a website uses it as a parameter, this error will appear.

Here are the top 5 fixes for the SSL_ERROR_NO_CYPHER_OVERLAP error.

Fix 1: Updating the Firefox Browser.

The first and most basic solution to this problem is to make sure you’re running the most recent version of Firefox. This is something you should do frequently to make your internet experience as smooth as possible.

To get the latest version of Firefox, open it, and then follow the given steps:

Step 1: Click the hamburger menu button, and then go to Help > About Firefox

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Step 2: If there are any updates available, Firefox should start downloading them right away. When the download is finished, go ahead and click the Restart to Update Firefox button.

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Alternatively, you can download the most recent version of Firefox from the Mozilla website. Remember to uninstall your existing version from your computer before downloading it. Here is how to do it:

Step 1: On Windows, press the Windows + R keys together

Step 2: type “appwix.cpl” into the search box and press Enter.

Step 3: Locate Firefox in the program manager, right-click it and select Uninstall.

Fix 2: Checking TLS1 and SSL3 Encryption protocols

If the encryption protocols SSL3 and TSL1 are disabled, users may receive the message “secure connection failed” with the error code SSL_ERROR_NO_CYPHER_OVERLAP, as some websites require these protocols for connection.

Although SSL3 and TSL2 settings are no longer available in the current version, you can work around the problem by modifying some security variables.

Step 1: Select Security Options from the menu button.

Step 2: Select the Privacy & Security tab in the pop-up window. Then look for the Security section by scrolling down.

Step 3: Uncheck the box that says “Block hazardous and deceptive content.”

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After that, close the browser and reboot your computer. Restart Firefox and see whether you can access the website that was blocked by the SSL_ERROR_NO_CYPHER_OVERLAP error code.

Fix 3: Resetting the SSL3 and TLS Settings.

If the problem persists, the next step is to reset your TLS and SSL3 settings if you are using the most recent Firefox version. To connect to some websites, you’ll need to use the TLS and SSL3 protocols. If you’ve turned them off, that may be why you’re getting the “SSL_ERROR_NO_CYPHER” issue. Here is how to do it:

Step 1: In the address(URL) bar, type “about:config” to reset them.

Step 2: Accept the risk and proceed despite the notification “Proceed with Caution,” which keeps you from making critical changes to your web browser by accident.

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Step 3: Firefox’s method of prevention is this caution. To continue, click Accept the Risk and Continue.

Step 4: Type “tls” in the search bar on the next Advanced Preferences screen: This will surely generate a list of all your TLS configurations:

Step 5: Look for any values that are bolded, as these are the ones that have recently changed. Right-click any bolded values and select Reset to return them to their default settings.

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Then, for SSL3, follow the same steps. Type “ssl3” into the search bar, and then reset any recently changed values:

Also, double-check that the following two entries are set to false:

  • security.ssl3.dhe_rsa_aes_128_sha
  • security.ssl3.dhe_rsa_aes_256_sha

Remember that disabling these options is critical for security reasons.

Fix 4: Changing the TLS Version Fallback.

Changing the TLS version to bypass is a fantastic option, however, it should not be used for every website. Here is how to do it:

Step 1: Look for security.tls.version.fallback-limit in Firefox’s about: config section.

Step 2: Set the value to zero.

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Step 3: Set the value of security.tls.version.min to 0 as well.

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Step 4: Check to see if you can get on the webpage.

If you change these values, your browser will become less secure. So, if it’s essential, go ahead and do it. Make a point of resetting it afterward.

Fix 5: Contacting the web host.

If this is just happening on one website, it’s a server-side problem. The issue can only be resolved by the server administrator. This typically occurs when a website still uses the RC4-Only Cypher Suite and the server’s ‘security.tls.unrestricted rc4 fallback’ option is set to false. For such cases, you should directly contact the web host provider or the server administrator and take their assistance in resolving the error.


Even though this error seems a lot complicated and trickier, you can resolve it by following the above-mentioned steps. This is not something that stays forever and you cannot resolve it on.