Did you post your question using the computer that has the problem? If so, did Firefox object to this site's certificate or does the problem seem to occur only on certain sites?

A common reason for secure certificate errors is that Firefox is not set up to work with a feature of your security software that intercepts and filters secure connections. In that process, the software presents Firefox with a "fake" certificate for the site, so until Firefox is set up to trust the software, it will always object to those certificates. Software with this feature includes avast! 2015, ESET, Kaspersky, and BitDefender.

Unfortunately, these errors also can be caused by malware, so it definitely makes sense to investigate.

If you visit Wells Fargo in a different browser and click the padlock icon in the address bar and view the certificate (in Chrome, this is under Connection), does the issuer list match up with the attached? Note that the tab names may be different in other browsers. If it doesn't match, what do you see?

I use the same security software on both computers. The desktop runs windows 7, the laptop Windows 8.1.

The issuer of the security certificate is the same in Chrome and Firefox although Chrome claims Wells Fargo is using obsolete cryptography, TLS 1.2. The odd thing is, I get the message I mentioned sometimes when trying to log on, sometimes not. Sometimes, I am already logged on and surfing back and forth between accounts and it happens when I am clicking on an account. I go back and re-logon and click the same account and things go fine for a while, if I can logon again, that is. The problem is sporatic.

I started having the same problem with my Safari browser and chose the option in Safari to "reset safari" and the problem stopped.

So, since you mentioned the possibility of malware, I guess I should check into that. Sounds like it may be the problem. Thank you for your response and for teaching me something I didn't know about that lock icon on the url line!

Can you attach a screenshot of the Security tab in the Network monitor that shows the settings of the first (main HTML file)?

• https://developer.mozilla.org/Tools/Network_Monitor

Sporadic is troubling, but it's only sporadic in Firefox and not in other browsers?

Could you check your Firefox connection setting and, if it's set to "Auto-detect" change it to either "Use system proxy settings" or "No proxy":

"3-bar" menu button (or Tools menu) > Options > Advanced > Network mini-tab > "Settings" button

Connection setting is "no proxy".

Here is attachment requested by cor-el

Edit: Also attaching copy of what I'm talking about. In this case, all I was doing was "sitting" at my account info, while I looked back and forth at it as I paid bills.

I did scans last night with Windows Defender, Malware Bytes and SuperAntiSpyware, cleaned up everything they found and it's still happening.

It would be useful to see the certificate details for when Firefox does not accept the certificate, but that is more difficult to accomplish.

You could reinstall using the following procedure to rule out problems in Firefox's program files:

Clean Reinstall

We use this name, but it's not about removing your settings, it's about making sure the program files are clean (no inconsistent, corrupted, or alien code files). As described below, this process does not disturb your existing settings. Do NOT uninstall Firefox, that's not needed.

(1) Download a fresh installer for Firefox 38.0.5 from https://www.mozilla.org/firefox/all/ to a convenient location. (Scroll down to your preferred language.)

(2) Exit out of Firefox (if applicable).

(3) Rename the program folder, either:

(64-bit Windows folder names)

C:\Program Files (x86)\Mozilla Firefox

to

C:\Program Files (x86)\OldFirefox

(32-bit Windows folder names)

C:\Program Files\Mozilla Firefox

to

C:\Program Files\OldFirefox

(4) Run the installer you downloaded in #1. It should automatically connect to your existing settings.

Can you get Firefox reinstalled?

Note: Some plugins may exist only in that OldFirefox folder. If something essential is missing, look in these folders:

• \OldFirefox\Plugins
• \OldFirefox\browser\plugins

Will my bookmarks and history stay intact if I follow that procedure, jscher 2000?

Hi SallyMae123, that procedure does not touch the settings folder.

If you want to be doubly sure, you can back it up. This article has suggestions for that: Back up and restore information in Firefox profiles.

If after the "clean reinstall" Firefox suggests a Refresh to speed things up, ignore that suggestion for the time being.