Separate Issue; Your System Details shows;

Installed Plug-ins

Shockwave Flash 21.0 r0 Shockwave Flash 23.0 r0
Having more than one version of a program may cause issues. You must remove the older programs. Then get the current full installer.

Flash: Grab the uninstaller from here: Uninstall Flash Player | Windows Uninstall Flash Player | Mac

Then reinstall the latest version.

Note: Windows users should download the active_x for Internet Explorer. and the plugin for Plugin-based browsers (like Firefox).

Note: Windows 8 and Windows 10 have built-in flash players and Adobe will cause a conflict. Install the plugin only. Not the active_x.

Flash Player Version: 23.0.0.185 Flash Player (Linux) Version 11.2.202.637

https://get.adobe.com/flashplayer/ Direct link scans current system and browser Note: Other software is offered in the download.

https://get.adobe.com/flashplayer/otherversions/ Step 1: Select Operating System Step 2: Select A Version (Firefox, Win IE . . . .) Note: Other software is offered in the download.

Happened right after 49.0.2 update

Major sites display the "problem loading: Server not found" page

twitter nfl.com imdb facebook whitehouse.gov yahoo.com websleuths

There is security software like Avast, Kaspersky, BitDefender and ESET that intercept secure connections and send their own certificate.

http://www.ehow.com/how_11385212_troubleshoot-reset-connection-firefox.html

https://support.mozilla.org/en-US/kb/server-not-found-connection-problem

https://support.mozilla.org/en-US/kb/firefox-cant-load-websites-other-browsers-can

https://support.mozilla.org/en-US/kb/firefox-and-other-browsers-cant-load-websites

https://support.mozilla.org/en-US/kb/secure-connection-failed-error-message

https://support.mozilla.org/en-US/kb/connection-untrusted-error-message

http://kb.mozillazine.org/Error_loading_websites

https://www.bing.com/search?q=web+site+access+denied

https://support.mozilla.org/kb/troubleshoot-SEC_ERROR_UNKNOWN_ISSUER

This Connection is Untrusted is sometimes caused because the computer system clock is wrong. Check the time / date / time zone settings.

Hi MartinKnauber, Firefox is indicating that the certificate it received for the site didn't meet the validation criteria. That could be caused by Firefox not being set up to work with your security software, by overly strict settings, or by some new malware that can trick other browsers but not Firefox. We want to help you get to the bottom of that.

Could you provide more detail from the error page to help us drill down to the solution? Often the page will have an "Advanced" button which opens a panel with technical detail that helps us get there. Can you copy/paste that or anything else that looks helpful?

Hi jscher2000, thanks for your reply. Unfortunately there is no "advanced" button on the page. I have had this problem several times in the past and then simply went to another browser to get to where I needed to go. But my point is that just reading forums or googling for solutions every time I encounter a problem is simply a luxury I no longer have. When I still went to school I had lots of time to troubleshoot stuff all day long, but now I don't. While there may be simple solutions to issues like this, there comes a point where I just can't spend any more time on fixing stuff and I just need to move on. And that is exactly what I'm doing now - regretfully, I admit because I always liked Firefox, but if chrome and MS Edge simply help me do what I need to without a hitch while Firefox forces me to take time off my actual work to fix stuff, then I simply have to move to those programs that work. But thanks for trying to help.