Firefox Edge Browser SSL_ERROR_RX_RECORD_TOO_LONG: How to Fix It

Q: What causes the SSL_ERROR_RX_RECORD_TOO_LONG error in Firefox?

This error is triggered when Firefox receives an SSL/TLS data record that exceeds the maximum allowed size. The most common cause is a proxy server, corporate firewall, or antivirus software intercepting the HTTPS connection and sending plain HTTP data on port 443 — a port Firefox expects to be encrypted. Misconfigured routers with deep packet inspection and corrupt browser profiles are also frequent causes.

Q: Does SSL_ERROR_RX_RECORD_TOO_LONG mean the website is down?

Not necessarily. The error usually indicates a problem on your end — such as a proxy, VPN, or security software interfering with the connection — rather than the website being offline. Try opening the same URL in a different browser like Chrome or Edge. If it loads fine in another browser, the issue is specific to your Firefox configuration or a local network setting.

Q: How do I fix SSL_ERROR_RX_RECORD_TOO_LONG on a corporate or school network?

On managed networks, you typically cannot change proxy or firewall settings yourself. Contact your IT helpdesk and describe the error and the specific URL you are trying to visit. The administrator may need to add an SSL inspection exception for that site or correct a misconfigured proxy rule. You can also ask whether the network uses SSL/HTTPS deep packet inspection, which is a frequent source of this error.

Q: Can antivirus software cause SSL_ERROR_RX_RECORD_TOO_LONG in Firefox?

Yes. Many antivirus programs include an HTTPS or SSL scanning feature that acts as a local proxy to inspect encrypted traffic. If this feature is misconfigured or incompatible with a specific website's TLS setup, it can cause SSL_ERROR_RX_RECORD_TOO_LONG. To test this, temporarily disable the HTTPS scanning or web shield feature in your antivirus settings — not the entire antivirus — and reload the page. If the error disappears, add an exception for the affected site in your antivirus software.

Q: Is SSL_ERROR_RX_RECORD_TOO_LONG a security risk I should worry about?

The error itself is not a sign that your computer is infected or compromised. It means Firefox detected something unexpected in the SSL connection and blocked it as a precaution, which is actually Firefox protecting you. However, if you consistently see this error only on one specific website, that site's server may have a misconfigured SSL certificate or TLS settings — in which case you should avoid entering sensitive information on that site until the issue is resolved by the site owner.

Abstract

The SSL_ERROR_RX_RECORD_TOO_LONG error in Firefox means the browser received a data packet during a secure (HTTPS) connection that is far larger than the SSL/TLS protocol allows. This almost always happens because a proxy server, firewall, or network device is intercepting your connection and sending back plain HTTP traffic on a port that Firefox expects to be encrypted. The good news is this error is usually fixable within minutes by adjusting your proxy settings, checking your network configuration, or clearing corrupted browser data.