How to Fix PR_END_OF_FILE_ERROR in Browsers

Encountering strange and unhelpful browser errors can be extremely frustrating, especially when you’re simply trying to access a website. One cryptic error that users, particularly those using Mozilla Firefox, occasionally run into is PR_END_OF_FILE_ERROR. Despite its technical and intimidating name, it usually has straightforward causes and solutions. This guide will demystify the error, explain why it happens, and walk you through practical steps to fix it.

TL;DR – Quick Summary

The PR_END_OF_FILE_ERROR usually appears when there’s a problem with SSL/TLS handshake during a website connection. It’s most common on Firefox, and is generally caused by security software, proxy configurations, or corrupted browser files. Getting rid of the error often involves resetting network settings, disabling VPNs or proxies, or tweaking browser configurations. It’s usually solvable within minutes once you follow the right steps.

What is PR_END_OF_FILE_ERROR?

This error message appears when your browser terminates a secure connection because no suitable encryption algorithms were agreed upon with the server. In simpler terms, it means Firefox (or a similar browser using Network Security Services – NSS) can’t complete a secure connection, so it stops trying and displays the error instead.

This problem rarely originates from the website itself. More often, changes on your local system or browser settings are to blame. Common culprits include:

• Faulty or misconfigured VPN or proxy software
• Overzealous antivirus software scanning HTTPS connections
• Corrupted Firefox profile or browser configurations
• Interference from third-party browser extensions
• Misconfigured system network settings

Step-by-Step Fixes for PR_END_OF_FILE_ERROR

1. Disable VPN or Proxy Connections

If you’re using a VPN or proxy, try disabling them temporarily. These services can modify how your browser connects to the internet, including affecting the SSL/TLS handshake process.

To disable proxy settings in Firefox:

1. Click the menu icon (three horizontal lines) in the upper-right corner.
2. Select Settings > General.
3. Scroll down to Network Settings and click on Settings….
4. Select No proxy and click OK.

If you are using a standalone VPN app (like NordVPN or ExpressVPN), simply disconnect and check if the error goes away. If it does, the issue lies with how the VPN handles encrypted connections.

2. Check Your Antivirus or Firewall Settings

Some antivirus programs are configured to scan secure connections. This might interfere with your browser’s ability to properly initiate SSL/TLS handshakes.

Try the following:

• Disable HTTPS scanning in your antivirus software (Exact steps depend on your antivirus).
• Temporarily disable your firewall and antivirus software to see if the error persists.
• If the error disappears, consider switching to a different antivirus or adjusting its settings.

Note: Only disable security software as a temporary test. Always ensure you re-enable protection afterward.

3. Refresh or Reset Firefox

Your Firefox profile holds your browsing data, history, saved passwords—and sometimes corrupted or conflicting configurations too. You can refresh Firefox to reset settings without deleting personal data.

To refresh Firefox:

1. Type about:support in the Firefox address bar and press Enter.
2. Click the Refresh Firefox button on the right-hand side.
3. Confirm when prompted.

Refreshing resolves configuration conflicts that may cause SSL/TLS errors like PR_END_OF_FILE_ERROR.

4. Disable Firefox Extensions

Extensions can influence how Firefox handles network connections. Ad blockers, privacy tools, or security extensions can sometimes block legit TLS handshakes.

To disable extensions:

1. Go to the Firefox menu and select Add-ons and themes.
2. Click on Extensions.
3. Disable each extension one by one, and then try reloading a site each time.

If the issue vanishes after disabling an extension, you can identify and remove the problematic one permanently.

5. Adjust “about:config” Settings

Advanced users can reset specific Firefox network settings that may be misconfigured. Only follow this route if you’re comfortable with in-depth browser configurations.

To reset network parameters:

1. Type about:config into the Firefox address bar.
2. Click Accept the Risk and Continue when prompted.
3. Search for parameters like security.tls.version.min, security.tls.version.max, or anything you’ve manually modified.
4. Click the reset icon next to each to restore defaults.

This will return encryption protocols to their default values and might fix connection problems caused by overly strict settings.

6. Clear SSL State on Your System

Sometimes cached SSL certificates or settings on your machine can interfere with new secure connections.

For Windows users:

1. Open Control Panel > Internet Options.
2. Go to the Content tab and click on Clear SSL state.
3. Restart Firefox and try visiting the problematic site again.

What If the Problem Persists?

If none of these methods resolve the issue, it’s time to consider some deeper troubleshooting methods:

• Try using another browser like Chrome or Edge to check if the issue is browser-specific.
• Restart your router or modem to clear out any DNS or networking hiccups.
• Create a new Firefox profile from scratch and try visiting the same site again.
• Check with your ISP, especially if they apply additional filters or security checks that could impact connections.

Preventing Future SSL Errors

While you can’t always control when a browser throws a cryptic error, you can take some simple steps to reduce the chances of it happening again:

• Keep your browser updated regularly.
• Avoid tinkering with advanced settings unless you know what you’re doing.
• Use reliable antivirus software that doesn’t interfere with HTTPS traffic excessively.
• Avoid installing shady browser extensions or modifying network configurations without backups.

Conclusion

The PR_END_OF_FILE_ERROR can be an annoying roadblock, especially when you’re unsure what’s causing it. Fortunately, most of the fixes are simple, quick, and don’t require expert-level skills. By methodically working through VPN, antivirus, Firefox, and network settings, you’ll most likely identify the source and eliminate the error. If all else fails, there are plenty of tools and communities online to help you dig deeper into your specific case.

Let this guide be your go-to solution the next time Firefox cryptically decides to drop the connection and throw a mysterious file-ending error!