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Secure Connection Failed Errors on Most Websites

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  • 1 有這個問題
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  • 最近回覆由 wordsmithfl

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Starting on October 18, I've had problems accessing most websites. I get security errors such as:

Secure Connection Failed Error code: SSL_ERROR_RX_RECORD_TOO_LONG

Secure Connection Failed Error code: PR_END_OF_FILE_ERROR

This problem occurs only with Firefox. It doesn't happen with Chrome (which I had to use to post here).

A few sites work, but not many.

I tried reinstalling the latest version of Firefox but that didn't make any difference.

Suggestions? Thanks in advance.

Starting on October 18, I've had problems accessing most websites. I get security errors such as: Secure Connection Failed Error code: SSL_ERROR_RX_RECORD_TOO_LONG Secure Connection Failed Error code: PR_END_OF_FILE_ERROR This problem occurs only with Firefox. It doesn't happen with Chrome (which I had to use to post here). A few sites work, but not many. I tried reinstalling the latest version of Firefox but that didn't make any difference. Suggestions? Thanks in advance.

被選擇的解決方法

Hi wordsmithfl

Those two errors — SSL_ERROR_RX_RECORD_TOO_LONG and PR_END_OF_FILE_ERROR — usually mean something is interrupting Firefox’s secure connection before it reaches the website. Here are a few things you can check:

1. Check Antivirus / Firewall software

Some antivirus programs (like Avast, Kaspersky, BitDefender, etc.) intercept HTTPS traffic and can break Firefox’s SSL connections. Try this:

  • Temporarily disable “HTTPS scanning” or “web protection” in your antivirus settings.
  • Restart Firefox and test again.
  • If that fixes it, re-enable protection but leave HTTPS scanning off.

2. Verify proxy settings

  • Go to Settings → General → Network Settings → Settings…
  • Make sure “No proxy” or “Use system proxy settings” is selected.
  • If a manual proxy is listed, clear it and try again.

3. Disable DNS over HTTPS temporarily

  • Go to Settings → Privacy & Security → DNS over HTTPS and uncheck “Enable DNS over HTTPS.”
  • Restart Firefox and test a few sites.
  • If it starts working, your DNS provider or network may be blocking DoH requests

4. Try Troubleshoot Mode

Menu ☰ → Help → Troubleshoot Mode… → Restart. This disables extensions and custom settings temporarily. If sites load in that mode, one of your add-ons or settings is the cause.

5. If still broken

Please share:

  • Which antivirus or VPN you’re using
  • Whether it happens on all networks (e.g. Wi-Fi vs. hotspot)

That will help narrow down whether something external is interfering with Firefox’s HTTPS connections.

Most users with these exact error codes find it’s caused by security software or proxy settings after a Windows or Firefox update. Disabling HTTPS scanning or resetting the network settings usually fixes it.

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選擇的解決方法

Hi wordsmithfl

Those two errors — SSL_ERROR_RX_RECORD_TOO_LONG and PR_END_OF_FILE_ERROR — usually mean something is interrupting Firefox’s secure connection before it reaches the website. Here are a few things you can check:

1. Check Antivirus / Firewall software

Some antivirus programs (like Avast, Kaspersky, BitDefender, etc.) intercept HTTPS traffic and can break Firefox’s SSL connections. Try this:

  • Temporarily disable “HTTPS scanning” or “web protection” in your antivirus settings.
  • Restart Firefox and test again.
  • If that fixes it, re-enable protection but leave HTTPS scanning off.

2. Verify proxy settings

  • Go to Settings → General → Network Settings → Settings…
  • Make sure “No proxy” or “Use system proxy settings” is selected.
  • If a manual proxy is listed, clear it and try again.

3. Disable DNS over HTTPS temporarily

  • Go to Settings → Privacy & Security → DNS over HTTPS and uncheck “Enable DNS over HTTPS.”
  • Restart Firefox and test a few sites.
  • If it starts working, your DNS provider or network may be blocking DoH requests

4. Try Troubleshoot Mode

Menu ☰ → Help → Troubleshoot Mode… → Restart. This disables extensions and custom settings temporarily. If sites load in that mode, one of your add-ons or settings is the cause.

5. If still broken

Please share:

  • Which antivirus or VPN you’re using
  • Whether it happens on all networks (e.g. Wi-Fi vs. hotspot)

That will help narrow down whether something external is interfering with Firefox’s HTTPS connections.

Most users with these exact error codes find it’s caused by security software or proxy settings after a Windows or Firefox update. Disabling HTTPS scanning or resetting the network settings usually fixes it.

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Hello Nathan --

Wouldn't you know, now it's working on its own without my trying any of the above steps. I suspect it might have had something to do with the massive outages experienced by many services over the weekend.

I got your email while at lunch. When I came home, I turned on my PC again and Firefox was working fine. Go figure.

But I'll keep your instructions in case it happens again. Thank you for all the details.

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