How to Fix PR_END_OF_FILE_ERROR: 3 Methods That Work

How to Fix PR_END_OF_FILE_ERROR: 3 Methods That Work

Most websites implement a secure connection protocol using Secure Sockets Layers (SSL) or Transport Layer Security (TLS). While this secure connection creates a safe browsing experience, it can also trigger some errors that may frustrate users.

One of such messages is PR_END_OF_FILE_ERROR – Firefox browser may throw this error from time to time. This article will explain what it is, its causes, and three simple ways to fix the PR_END_OF_FILE_ERROR secure connection failed error.

Error typeBrowser error
Error variationsSecure Connection Failed
Error causesVPN or proxy interference
Incorrect cipher variants
Corrupted Firefox profile
Third-party security software interference

What Causes the PR_END_OF_FILE_ERROR (Secure Connection Failed) Error?

PR_END_OF_FILE_ERROR error message

The PR_END_OF_FILE_ERROR error message appears when the Mozilla Firefox browser can’t establish a secure connection. It is a Firefox-specific error and won’t appear in any other browser. Thus, this often affects many websites you try to visit, as the problem is on the client-side.

To understand why PR_END_OF_FILE_ERROR happens, we have to understand the process of establishing a secure connection between a browser and a website.

Your browser has a cipher suite – a set of algorithms that makes a secure connection over an encrypted protocol possible. When you visit a website that uses SSL or TLS, the browser runs through the cipher suite until it finds a matching algorithm for the connection.

However, if Firefox reaches the end of the cipher suite file and doesn’t find a match, it results in the PR_END_OF_FILE_ERROR message.

In general, this error has four possible causes:

  • Virtual Private Network (VPN) or proxy server interference. A VPN and a proxy server act as a middle man between your computer and website server, hiding your IP address and location. If not configured correctly, VPN and proxy services can trigger PR_END_OF_FILE_ERROR.
  • Incorrect cipher variants. It may happen when you’ve modified SSL settings on your computer or browser. In this case, the browser enforces a cipher version that’s not supported either by Firefox or the website.
  • Corrupted Firefox profile. Synchronization issues between desktop and mobile browsers can corrupt a Firefox profile, triggering the Firefox secure connection failed error.
  • Third-party security software. Antivirus software can sometimes misidentify safe websites and block your access to them.
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Multiple aspects can trigger the PR_END_OF_FILE_ERROR secure connection failed issue. We will cover three ways to fix it from different possible sources of the error – the Firefox settings, a proxy or VPN connection, and third-party security software.

Before proceeding to the different methods to fix the secure connection failed error, check if the website is down for all visitors or whether you’re the only one unable to access it.

1. Go Through Your Firefox Settings

Since PR_END_OF_FILE_ERROR is a Firefox-specific issue, we’ll start by reviewing the browser settings.

Reset Firefox SSL Settings

You may have modified the browser’s SSL settings, triggering the issue. Refreshing Firefox settings can resolve this secure connection error. Follow these steps to do so:

  1. Click the hamburger menu at the top-right corner and click Help.
Firefox help menu
  1. Select More Troubleshooting Information.
More troubleshooting information on Firefox
  1. The Troubleshooting Information tab will show the diagnostics. At the top-right corner, click the Refresh Firefox button under Give Firefox a tune up.
Button to refresh Firefox
  1. A prompt pop-up screen will appear. Click the Refresh Firefox button.
Confirmation prompt to refresh Firefox.

The browser will automatically close, and a new window will appear, showing the reset progress. Once it restarts, the browser will use its default configuration, including the SSL settings.

Revisit the website to see whether the reset resolved the issue. If the error persists, try the next method.

Disable DNS Over HTTPS

When you try to open a website, your browser sends a DNS request to the server. DNS over HTTPS is a protocol that sends these requests through HTTPS.

Enabling it prevents malicious attackers from eavesdropping and seeing your online activity. Unfortunately, this feature can also trigger the PR_END_OF_FILE_ERROR.

However, disabling it is a quick fix. Follow these steps to disable DNS over HTTPS:

  1. Click on the hamburger menu at the top-right corner and click Settings.
Firefox settings
  1. On the General screen, scroll down to the bottom, and you’ll find the Network Settings section. Click Settings.
Network settings on Firefox
  1. At the bottom of the Connection Settings window, there’s an Enable DNS over HTTPS option. Uncheck the box and click OK.
DNS over HTTPS setting on Firefox

Restart the browser and see if this resolved the secure connection failed error.

Create a New Firefox Profile

If all the previous methods for PR_END_OF_FILE Firefox error didn’t work, your Firefox profile might be corrupted. So, you will need to create a new profile.

We suggest exporting bookmarks before creating a new profile. Therefore, if this method resolves the error, you can easily import the bookmarks to use on your new Firefox browser profile.

  1. Open the bookmark manager by clicking CTRL+Shift+O. Alternatively, click the hamburger menu, select Bookmarks, and click Manage bookmarks at the bottom.
  2. Select All Bookmarks.
Firefox bookmarks manager
  1. Click Import and Backup and select Export Bookmarks to HTML.
Export bookmarks on Firefox
  1. A new window will appear. Select the folder to save the bookmark data and click Save.

Now, follow these steps to create a new profile.

  1. Type about:profiles in the address bar and press Enter.
  2. Click the Create a New Profile button.
Create a new profile on Firefox
  1. The Create Profile Wizard will appear. Follow the on-screen instructions.
Create profile wizard on Firefox
  1. Once it’s done, the new profile will appear on the profile manager page.
  2. Click Launch profile in new browser.
Launch a new profile on Firefox

Try to revisit the website with the new profile. If it works, then the corrupt Firefox profile was the main issue causing secure connection failed error.

Now all you have to do is import the bookmarks to the new profile. Similar to the export bookmark process, open the bookmark manager and choose Import Bookmarks from HTML, then select the saved file.

2. Turn Off Your VPN or Proxy

Browsing the internet using a proxy or VPN server can also trigger the PR_END_OF_FILE_ERROR. These services interfere with the connection by acting like a middle man, which sometimes makes the connection protocol unable to find the correct cipher suites.

If that’s the case, disabling VPN or proxy should fix the PR_END_OF_FILE_ERROR.

The steps to turn it off depend on the VPN application you use but, most of the time, it’s a simple process. Below is an example of the NordLayer VPN app’s interface:

VPN turn-off button

If you use a proxy connection, you have to disable it from the system’s proxy settings, and the steps are different for Windows and macOS users.


Turn off the proxy server in the system settings. Here are the steps to do so:

  1. Open the Windows Settings and go to Network and Internet.
Network and internet settings on Windows
  1. Select Proxy on the left panel.
  2. Scroll down to the Manual proxy setup section and switch off Use a proxy server.
Proxy server setting on Windows
  1. Reboot the computer so that the change takes place and revisit the website using the Firefox browser.


In macOS, you have to uncheck all proxy protocols, like so:

  1. Open System Preferences and select Network.
Network settings on MacOS system preferences
  1. Select Wi-Fi on the left panel, then click the Advanced button.
Wi-Fi advanced settings on MacOS
  1. Open the Proxies tab. Uncheck all items on the Select a protocol to configure box and click OK.
Proxy protocols on MacOS
  1. Reboot your computer and use the Firefox browser to revisit the website.

Firefox Proxy Settings

It’s also possible that the proxy connection is active on your Firefox connection settings, causing PR_END_OF_FILE_ERROR. Follow these steps to turn it off:

  1. Click on the hamburger menu at the top-right corner and select Settings.
  2. Scroll down until you find the Network Settings section and click Settings.
Network settings on Firefox
  1. The Connection Settings window will appear – you’ll find Configure Proxy Access to the Internet at the top. Check the No proxy option and click OK to save.
Proxy settings on Firefox, highlighting the "No Proxy" option

Now, restart Firefox to see if it worked.

3. Temporarily Disable Security Software

This method is more applicable to Windows users, as the operating system often relies on third-party security software.

Some security or antivirus software like Kaspersky, BitDefender, and ESET may perceive cipher suites as potential threats. In that case, they intercept the connection and use their secure protocol, resulting in Firefox secure connection failed error.

You might consider switching off the software completely, but doing so will expose your computer to security risks.

We recommend disabling only the real-time protection on your antivirus software, if possible. This feature tracks your activity and intercepts the network connection immediately if it finds any threats.

If it can’t be switched off manually, the only option is to disable the software completely. The method is different depending on the software you use. In general, you can find the settings on the dashboard or configuration section.

Endpoint Security interface

After you disable the software, reboot the computer and try revisiting the website. If the current security software is the main cause of the issue, try to replace it with one that doesn’t trigger PR_END_OF_FILE_ERROR.


The Mozilla Firefox secure connection failed error happens when your browser can’t find a matching cipher suite to establish a secure connection with the website.

This might be caused by a misconfiguration on the browser settings, VPN or proxy problems, or security software interference.

To recap, here is what you can do to fix this Firefox error:

  1. Go through the Firefox settings. The easiest way to fix this secure connection error is to reset the Firefox settings. If that doesn’t work, disable DNS over HTTPS or create a new Firefox profile.
  2. Disable the VPN client or proxy service. Your VPN and proxy service can interfere with the connection. Try turning them off to resolve the error.
  3. Disable security software. Some security software might see cipher suites as security threats. Turn off real-time protection on the software if possible. Otherwise, disable the software temporarily and, if that resolves the secure connection error, look for alternative software.


Here are some frequently asked questions about the error.

What Are Some of the Best Practices for Avoiding the PR_END_OF_FILE_ERROR?

Ensure that your website and server are up-to-date and running the latest versions of software to avoid the PR_END_OF_FILE_ERROR. Use secure and reliable web hosting with adequate resources, such as Hostinger. Minimize the use of third-party scripts and plugins, which can cause conflicts and errors.

What Are Some of the Tools That Can Help Me Diagnose and Fix the PR_END_OF_FILE_ERROR?

Some of the tools that can help diagnose and fix PR_END_OF_FILE_ERROR include Developer Tools, Wireshark, and Fiddler. These tools allow you to analyze network traffic and identify issues with SSL certificates, server configuration, and other potential causes of the error.

The author

Leonardus Nugraha

Leo is a Content Specialist and WordPress contributor. Armed with his experience as a WordPress Release Co-Lead and Documentation Team Representative, he loves sharing his knowledge to help people build successful websites. Follow him on LinkedIn.