Here are some screenshots.

Clear the Cache Firefox/Tools > Options > Advanced > Network > Cached Web Content: "Clear Now"

and

Remove Cookies Firefox/Tools > Options > Privacy > Cookies: "Show Cookies"

If there is still a problem, Start Firefox in Safe Mode
While you are in safe mode;
Firefox Options > Advanced > General.
Look for and turn off Use Hardware Acceleration

Tried all that, didn't work.

UPDATE: The problem resolved itself on its own. I walked away from the machine out of sheer frustration. Came back 2 days later, and everything worked fine. Must've been a glitch with the website.

I've got exactly the same problem on both v 29 and 30. The thing is, my desktop computer is fine, my BRAND NEW laptop, stripped of ALL it's HP crapware and just using MSE, can display ANY webpage ok EXCEPT anything to do with Mozilla Firefox add-ons, AND the browser can't install any add-ons. I've tried all the usual banal "fixes", including switching off hardware acceleration, but all I get is plain-text for the pages as per sample, and no install of add-ons themselves. Again, note that this is ONLY a problem on the laptop, not on my desktop. They are both plugged into the same router (both through LAN / ethernet), and so therefore they should both work properly. I don't want to hear any stupid suggestions about formatting and re-loading. Just damn-well fix it, please! I've already wasted more than an hour of my very valuable time on this ridiculous problem. And yes, I've even uninstalled Flash 14 just in case (even though Flash 14 is on my desktop and not causing any problems - yet).

Check the date and time in the clock on your computer: (double) click the clock icon on the Windows Taskbar.

• https://support.mozilla.org/kb/Secure+Connection+Failed

Hi Peter, has Firefox mentioned any problems with SSL certificates and if so, have you created any exceptions for sites?

The Add-ons site loads its style sheets from a content distribution network (CDN). Are you able to open these links directly (expect to see just a load of text):

• https://mozorg.cdn.mozilla.net/media/css/tabzilla-min.css
• https://addons.cdn.mozilla.net/media/css/zamboni/impala-min.css

After having stared grumpily at the computer screen for some time after posting my message, I suddenly realised that, despite having it checked it twice, the date was in fact wrong. For whatever reason, the date was set to yesterday - which is obviously where my mind still was, because when I saw the date I thought "Yes, that's the correct date". After I set the date to today, the problem went away. Curious that such a small issue should cause such a "profound" problem. Anyway, all sorted.

Great news! Never be afraid to double check everything.

One last thing. Please go to your 7:59 PM post and mark it as your solution so that others will know what to do.

Happy Computing.

I'm having the same issues.. the above links just give me a page load error.

"Are you able to open these links directly (expect to see just a load of text):

   https://mozorg.cdn.mozilla.net/media/css/tabzilla-min.css
   https://addons.cdn.mozilla.net/media/css/zamboni/impala-min.css "

It's a "refurbished" laptop, exact same make/model/os as my previous. Everything still works fine on the old.. but not on this one. Cache is cleared/cookies cleared. Even though I have no add-ons.. went through options and turned them/safe mode... no change... reset to default.. no change checked clock date/time (it was wrong, fixed it). still having issue The page loads through IE browser though. addons.mozilla.org has exceptions rights

Hi Palak86, on the clock, check all three of these:

• Date
• Time
• Time Zone

The OCSP "future response" error almost always is caused by a problem with one of those.