https://www.bing.com/search?q=pr_end_of_file_error

jamesafuf123 said] https://support.mozilla.org/en-US/questions/1264659#answer-1237475 my isp was blocking sites like that

Thanks, FredD, for responding...I have seen these links before on this topic. They are either too technical or do not fix my problem. To me, the interesting thing is that FF will not open ANY site - not just specific ones. This seems to suggest some kind of communication problem between FF and my computer....but I am not an expert. Nick

Type about:preferences#advanced<Enter> in the address bar.

Under Advanced, Select Network.

[56+] Type about:preferences#general<enter> in the address bar. Look for Network. +++++++++++++++++++++ Look for Configure How Firefox Connects and press the Settings button. If you are using a proxy, make sure those settings are correct. If there is no proxy, first try No Proxy. If there is a problem, then try System Proxy.

Some problems occur when your Internet security program was set to trust the previous version of Firefox, but no longer recognizes your updated version as trusted. Now how to fix the problem: To allow Firefox to connect to the Internet again;

• Make sure your Internet security software is up-to-date (i.e. you are running the latest version).
• Remove Firefox from your program's list of trusted or recognized programs. For detailed instructions, see

Configure firewalls so that Firefox can access the Internet. {web link}

I finally uninstalled my antivirus (Avira), as it refused to update. Rebooted the computer and FF worked no problem! I might reinstall Avira; do you have a recommendation for an antivirus program for mac? I know some say it does not need one, but..... Thanks

Different users will give you different answers. You should do your own research. https://www.bing.com/search?q=best+antivirus