How to Resolve the PR_END_OF_FILE_ERROR in Firefox

Having trouble with the “pr_end_of_file_error” in your Firefox browser? Don’t worry! In this guide, we’ll walk you through a variety of solutions to resolve this issue so you can get back to browsing seamlessly. The article also provides detailed information and helpful links to further assist you in understanding the problem and fixing it for good.

Understanding the PR_END_OF_FILE_ERROR

The “pr_end_of_file_error” is a security-related error that occurs in Firefox when there’s an issue with the SSL/TLS handshake between the browser and the server. Various factors, including outdated browser versions, cache or cookie issues, and conflicts with antivirus or firewall settings can trigger this error.


Updating Firefox to the Latest Version

One of the easiest and most effective solutions to fix the “pr_end_of_file_error” is to update your Firefox browser to the latest version. An outdated browser may have compatibility issues with the latest security protocols, causing the error. To update Firefox, follow these steps:

  1. Open Firefox and click on the menu button (three horizontal lines) in the upper-right corner.
  2. Select “Help” and then “About Firefox.”
  3. The About Mozilla Firefox window will open, and the browser will automatically check for updates.
  4. If an update is available, click “Restart to Update Firefox” and let the browser apply the update.

Updating Firefox ensures you have the latest security patches and bug fixes, which can help resolve the “pr_end_of_file_error.”


how to update firefox

Clearing Browser Cache and Cookies

Another common cause for the “pr_end_of_file_error” is corrupt or outdated cache and cookies. To clear your browser’s cache and cookies, follow these steps:

  1. Open Firefox and click on the menu button (three horizontal lines) in the upper-right corner.
  2. Select “Options” or “Preferences” (depending on your system).
  3. Click on “Privacy & Security” in the left sidebar.
  4. Scroll down to the “Cookies and Site Data” section and click on “Clear Data.”
  5. Check both “Cookies and Site Data” and “Cached Web Content” boxes, and then click on “Clear.”

clearing cookies in firefox

By clearing your browser’s cache and cookies, you eliminate any potential issues that could be causing the “pr_end_of_file_error.”

Checking Your Antivirus and Firewall Settings

Antivirus and firewall software can sometimes interfere with the SSL/TLS handshake process, leading to the “pr_end_of_file_error.” To resolve this, you can temporarily disable your antivirus and firewall or add an exception for Firefox. For detailed instructions, refer to your antivirus and firewall documentation or check these helpful guides on disabling antivirus software and managing firewall settings.

Disabling TLS 1.3

Though TLS 1.3 is designed to improve security and performance, it can sometimes cause the “pr_end_of_file_error” due to compatibility issues with certain websites. To disable TLS 1.3 in Firefox, follow these steps:

  1. In the Firefox address bar, type “about:config” and press Enter.
  2. Click on “Accept the Risk and Continue” to proceed to the advanced settings page.
  3. In the search bar, type “security.tls.version.max” to locate the relevant setting.
  4. Double-click on the “security.tls.version.max” entry, and change its value to “3” (which corresponds to TLS 1.2).
  5. Click “OK” to save the changes and close the window.

firefox about config


After disabling TLS 1.3, restart Firefox and check if the “pr_end_of_file_error” has been resolved. If the error persists, you can always revert the setting back to its original value by following the same steps and changing the value back to “4” (which corresponds to TLS 1.3). If you are out of options, you can check the Mozzilla forum if you wish.

Resetting Your Firefox Browser

If none of the previous methods have resolved the “pr_end_of_file_error,” resetting Firefox to its default settings may be a viable option. Keep in mind that this process will erase your browsing data, including bookmarks, history, and saved passwords, so be sure to back up your data before proceeding. To reset Firefox, follow these steps:

  1. Open Firefox and click on the menu button (three horizontal lines) in the upper-right corner.
  2. Select “Help” and then “Troubleshooting Information.”
  3. In the “Give Firefox a tune-up” section, click on “Refresh Firefox.”
  4. A confirmation window will appear. Click “Refresh Firefox” again to proceed with the reset.

Once the reset process is complete, Firefox will automatically restart. Check if the “pr_end_of_file_error” has been resolved.

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Gyula Virag
Gyula Virag

Gyula is a developer and a passionate geek father with a deep love of online marketing and technology. He always seeks challenging adventures and opportunities to create something permanent in the digital world.

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