

Virtual Private Network (VPN) or proxy server interference.In general, this error has four possible causes: 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. 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. Your browser has a cipher suite – a set of algorithms that makes a secure connection over an encrypted protocol possible. 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. Thus, this often affects many websites you try to visit, as the problem is on the client-side. It is a Firefox-specific error and won’t appear in any other browser.

The PR_END_OF_FILE_ERROR error message appears when the Mozilla Firefox browser can’t establish a secure connection.
