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refreshed firefox cannot open wibsite that IE can

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after refreshing Firefox tried to log on to a website that I could before and received -n error occurred during a connection to www.fusonet2.com. Peer's certificate has an invalid signature. (Error code: sec_error_bad_signature)

after refreshing Firefox tried to log on to a website that I could before and received -n error occurred during a connection to www.fusonet2.com. Peer's certificate has an invalid signature. (Error code: sec_error_bad_signature)

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I have cleared recent history and have the latest version of Firefox

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Spoiler Alert: Do you use Avast? If so, please try shutting down Windows and starting it back up again to trigger Avast to set up Firefox to work with its WebShield feature.

When you get secure connection errors for most secure sites immediately after a refresh, when everything was fine before, the problem usually is one of the following because a Refresh breaks the trust between Firefox and this external software:

(1) Firefox not being set up to work with your security software that intercepts and filters secure connections. Products with this feature include Avast, BitDefender, ESET, and Kaspersky; AVG has a Search Shield feature which can cause this error on search sites.

(2) On Windows 10, Firefox not being set up to work with the parental control software Microsoft Family Safety. (To test by turning it off, see: http://windows.microsoft.com/en-us/wi.../turn-off-microsoft-family-settings)

(3) Malware on your system intercepting secure connections.

So... which is it?

If you have any of those specific security products, that would be the first thing to check. We might be able to assist with specific next steps based on what you have if you tell us.


To gather further information, you could inspect a sample certificate to see whether that points to the culprit. If you want to try that now, here's how I suggest starting:

Load my test page at: https://jeffersonscher.com/res/jstest.php

You likely will get an error page. Expand the "I understand the risks" section and look for an Add Exception button.

Note: You don't need to complete the process of adding an exception -- I suggest not adding one until we know this isn't a malware issue -- but you can use the dialog to view the information that makes Firefox suspicious.

Click Add Exception, and the certificate exception dialog should open.

Click the View button. If View is not enabled, try the Get Certificate button first.

This should pop up the Certificate Viewer. Look at the "Issued by" section, and on the Details tab, the Certificate Hierarchy. What do you see there? I have attached a screen shot for comparison.