On the page where you get that error, could you click the "Advanced" button and then copy/paste the technical explanation that Firefox displays after that.

I may have to just cancel my firefox account. I would like to know why all of a sudden it is blocking my sites that I go to all the time. I want to turn off whatever is making it possible to block my accounts.

Boot the computer in Windows Safe mode with network support to see if that has effect in case security software is causing problems.

• http://www.bleepingcomputer.com/tutorials/how-to-start-windows-in-safe-mode/
• http://www.7tutorials.com/4-ways-boot-safe-mode-windows-10

I understand your frustration. If you could provide the information I requested, that will help lead to a proper diagnosis.

Your connection is not secure

The owner of secure1.sinclairoil.com has configured their website improperly. To protect your information from being stolen, Firefox has not connected to this website.

Learn more…

This is the response I get when I try to access my Sinclair Oil account to pay my bill. I will try more of the suggestions I have been given. Thank you so much for your help. I realize it is not a firefox problem. I've had problem with Windows trying to add updates to my account and it messes my e-mail system up.

Thanks, usually you will also find an "Advanced" button. Could you click the "Advanced" button and then copy/paste the technical explanation that Firefox displays after that.

If you can't inspect the certificate via "Add Exception" then try this:

Open the "Add Security Exception" window by pasting this chrome URL in the Firefox location/address bar and check the certificate:

• chrome://pippki/content/exceptionDialog.xul

In the location field of this window type or paste the URL of the website with the https:// protocol prefix (https://xxx.xxx).

• retrieve the certificate via the "Get certificate" button
• click the "View..." button to inspect the certificate in the Certificate Viewer

You can inspect details like the issuer and the certificate chain in the Details tab of the Certificate Viewer. Check who is the issuer of the certificate. If necessary then please attach a screenshot that shows the Certificate Viewer with the issuer.

The secure1.sinclairoil.com server doesn't send all intermediate certificates needed to build a complete certificate chain.

You can check the server via this website:

• https://www.ssllabs.com/ssltest/analyze.html?d=secure1.sinclairoil.com

Extra download 	GeoTrust DV SSL CA - G4
Fingerprint SHA1: 35e540f4d36e94d9005b18dce27ca2ae8ca0020d
Pin SHA256: 47vMpYDaFnUzDRQdNlsSppZ2DbMBfK5uwhBNakbz2n4=
RSA 2048 bits (e 65537) / SHA256withRSA

A server needs to send the full certificate chain that includes all required intermediate certificates. Firefox will automatically store intermediate certificates that servers send in the Certificate Manager for future use, so if you have visited a website that has send this intermediate certificate in the past then Firefox will not display the error page when you visit a server that doesn't send this intermediate certificate.

You can download the intermediate certificate via this link and import the certificate in the Certificate Manager.

• https://cryptoreport.geotrust.com/chainTester/webservice/validatecerts/certificate?certKey=issuer.intermediate.cert.71&fileName=GeoTrust%20DV%20SSL%20CA%20-%20G4&fileExtension=cer

Do NOT set any trust bits when importing the certificate as those are only required for trusted root certificates and should never be set for intermediate certificates.