I'll start with the most general suggestion:

When you have a problem with one particular site, a good "first thing to try" is clearing your Firefox cache and deleting your saved cookies for the site.

(1) Bypass Firefox's Cache

Use Ctrl+Shift+r to reload the page fresh from the server.

Alternately, you also can clear Firefox's cache completely using:

orange Firefox button (or Tools menu) > Options > Advanced

On the Network mini-tab > Cached Web Content : "Clear Now"

If you have a large hard drive, this might take a few minutes.

(2) Remove the site's cookies (save any pending work first). While viewing a page on the site, try either:

• right-click and choose View Page Info > Security > "View Cookies"
• Alt+t (open the classic Tools menu) > Page Info > Security > "View Cookies"

In the dialog that opens, you can remove the site's cookies individually.

Then try reloading the page. Does that help?

Does Firefox display any notification icons in the address bar? These usually appear to the left of the globe or padlock icon, and may indicate a problem with page security, a disabled plugin, or other relevant information. If you see an icon there, click on it for more information.

Could you try the site in Firefox's Safe Mode? That's a standard diagnostic tool to bypass interference by extensions (and some custom settings). More info: Use Troubleshoot Mode in Firefox.

You can restart Firefox in Safe Mode using

Help > Restart with Add-ons Disabled (Flash and other plugins still run)

In the dialog, click "Start in Safe Mode" (not Reset)

Any improvement?

Hi CJ, I got your message that the site works in Safe Mode. This usually indicates that one of your extensions is changing the page, either to remove annoyances or to enhance privacy. When you eventually exit Safe Mode, you can review your extensions (and access their Options) on the Add-ons page. Either:

• Ctrl+Shift+a
• orange Firefox button (or Tools menu) > Add-ons

In the left column, click Extensions.

Hopefully it's an easy fix, either making an exception for the site or turning something on or off.

If it works in Safe Mode and in normal mode with all extensions (Firefox/Tools > Add-ons > Extensions) disabled then try to find which extension is causing it by enabling one extension at a time until the problem reappears.

Close and restart Firefox after each change via "Firefox > Exit" (Windows: Firefox/File > Exit; Mac: Firefox > Quit Firefox; Linux: Firefox/File > Quit)

See also this article (link already posted above):

• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes