Is this is the only HTTPS site with that problem? That would be unusual.

Do the problem computers share a single router/firewall/proxy that may implement any filtering?

To investigate further, could you inspect the certificate? This is easiest if the error page has a section entitled "I understand the risks". In that case, you can 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.

Thank you for the prompt reply Jsher, the computers that I was testing are all wireless devices. I work at a public school that does have a proxy/filtering system in place by the dept of education, but my building has various access points all over, all under one ssid.

I'm not having any issues on IE or Chrome. The teacher who uses this device prefers to use firefox because the website/application works best through firefox according to some other coworkers. I also do not have issues accessing other HTTPS websites.

I'm not seeing where I can view the information you have provided. I don't even see the "I understand the risks page" This is the page I see when I land on the website. Please see attached.

Unfortunately, that variant of the error page doesn't have the relevant section. Here are couple other ways to check:

(1) In Firefox, load the following internal page in a new tab by pasting the URL to the address bar and pressing Enter:

chrome://pippki/content/exceptionDialog.xul

Then you can paste the URL of the page that won't load and try to "Get" the certificate so you can view it. This works some of the time, but not all of the time.

(2) In Chrome, click the padlock icon on the address bar, then in the panel that drops down, click Connection, then view certificate or certificate details (I can't remember). This should call up a dialog with similar information to Firefox's in a slightly different layout.

Hi again, so the first step with the pippki link did not work. Here is what I pulled from Chrome.

The computers in the school are imaged with a special windows image that the Dept of Ed gives us techs. I use my own laptop (mac) and I had no problem accessing that website via firefox. I wonder if it's a setting on the computer.

It's odd that the root certificate is named differently than when I visit. However, when I look at that cert more closely Chrome, it seems to be the same one (screen shot). I can't tell what's going on.

Two other thoughts:

(1) Could you check whether you saved a previous exception for this site?

"3-bar" menu button (or Tools menu) > Options > Advanced

Click the Certificates mini-tab, then the "View Certificates" button. This should open the Certificate Manager dialog.

In the Certificate Manager, click the Servers tab. Ignore servers whose name is listed as "*", those are special blocking rules. If you find one for nycenet go ahead and remove it, and then OK out of the dialog.

(2) Could you check your connection setting here:

"3-bar" menu button (or Tools menu) > Options > Advanced

Click the "Network" mini-tab and then the "Settings" button. Please try "No proxy" and see whether that makes any difference.

I don't see anything nycenet related under servers and nothing will work without the proxy, for good measure I turned it off and nothing it works.