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To fix the”err_ssl_version_or_cipher_mismatch” Error, just follow the simple steps in this article. Seeing this “unknown error” warning in your web browser could be scary, but it’s easy to fix. It happens when your web browser finds a problem with the SSL certificate version of the website.
When you visit a website that uses HTTPS, the browser and web server go through a number of processes to make sure the SSL/TLS connection and certificate are valid. The TLS handshake, checking the certificate against the certificate authority, and decrypting the certificate are some of these.
The error ERR_SSL_VERSION_OR_CIPHER_MISMATCH happens when a user’s browser can’t connect securely to an HTTPS and SSL-based web server. The problem could be with how the server is set up or with a user’s computer. You can also go to the official Microsoft support site for more information about this error.
Ways to Fix “err_ssl_version_or_cipher_mismatch” Error
Deactivate SSL/HTTPS Scanning
If you have an anti-virus or anti-malware program on your computer, you can turn off one feature for a short time. SSL Scan is done by computer security software, and it can be turned off.
The instructions below are for people who use Bitdefender because it is known that this security software can cause the ERR_SSL_VERSION_OR_CIPHER_MISMATCH problem. Remember that it is doing this to keep you secure, so you might want to turn the feature back on after you visit your favorite website.
- Open Bitdefender.
- Navigate to Modules > Web Protection.
- Click on Scan SSL to toggle it off.
Those that use Avast should perform the following:
- Open Avast. Go to Settings > Main Settings.
- Deselect Enable Web scanning and HTTPS scanning. We strongly suggest that you turn these back on once you visited your desired website.
Disable RC4 encryption
Since many years, people have been told not to use the RC4 encryption cipher. The major reason for this is that it is not very secure. In other words, RC4 is no longer thought to be a safe way to encrypt data, and if a site is trying to use it to encrypt data, it could lead to failures when trying to access it. Here’s how to solve it (remember to back up your registry before making any changes!)
- type in regedit in Windows search and press Enter.
- If User Account Control pop-up shows up, click Yes.
- Go to the following location (you can paste it at the top)”
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\Schannel\Ciphers
- Right-click on Ciphers and select New > Key.
- Name it RC4 40/128.
- Now right-click on it and select New > DWORD (32-bit) Value.
- Name it Enabled and double-click it.
- If the value is not set to 0, do so and press OK.
- Exit Registry Editor.
Delete Browser Cache and Cookies
- Open Google Chrome and go to Menu > Settings.
- Scroll down and click Advanced.
- Locate Clear browsing data and click on it.
- Then, select Cookies and other site data and Cached images and files, and press Clear data.
Enable TLS 1.3
- Open Google Chrome browser.
- Now, type chrome://flags into the address field and press Enter.
- Press CTRL + F, type TLS 1.3 and press OK to locate the section.
- Enable the TLS 1.3.
Disable QUIC protocol
When the QUIC protocol is turned on, Chrome can sometimes show the ERR_SSL_VERSION_OR_CIPHER_MISMATCH issue. Follow these steps to turn it off:
- Open Google Chrome browser.
- Type in chrome://flags into the address field and hit Enter.
- Press CTRL + F, type TLS 1.3 and click OK.
- Disable QUIC protocol from the drop down menu on the right.