Why couldn't I access the site?

I’m using another computer in my home right now. But on my main computer, I keep getting those “Problem Loading Page” screens. It says I don’t have a secure connection. Sometimes I could access the site for a while before it reverts back. Other websites work completely fine. It started happening only today.
 
Edit: I can access it at this moment, but it’s likely I’m going to get that dreading “Problem Loading” screen again.

The News Site says:
 
Hi all,
 
We’re seeing some issues caused by an update at our Certificate Authority affecting users of Firefox and HTTPS. We’re attempting to fix this and get everything ironed out but in the meantime you may want to try using Google Chrome or Internet Explorer.
 
Love,  
Clover
 
Strange that I myself haven’t had any issues on either of my operating systems and I’ve been using both Firefox and HTTPS the whole time.

@Background Pony  
I use Firefox… Sometimes the site works. But the site would be inaccessible at random times and re-accessible at random as well.
 
I guess that clears things up.

Has the issue been resolved yet? I heard some people using FF who had the same problem are able to access the site again. While I’m still not able to at all since this morning. Just need to know.

Okay as of a few minutes ago I finally started getting that issue as well (“that issue” if your problem came from the stuff reported in the news), and just simply switched my bookmark link to http instead of https - now everything’s just fine.
 
If anyone dislikes using a different browser then that is a way to get back in with Firefox.

I unchecked the Certificate Validation box on Advaned options. It has work so far without problems

@QuasarNova  

 
Thanks a lot there Bud!

@QuasarNova  
Remember to check it again after the problem goes away. The certs are validated for a reason.

@JP  
Sorry what reason?

@SeraphimDawn  
To make sure the certificate hasn’t been revoked. For example, if the certificate authority messes up, or the private key is leaked, then the certificate can’t be trusted anymore and it gets revoked.
 
I don’t know why this affects only Firefox and Opera users. Wikipedia says Chrome and IE supports OCSP, but maybe they ignore its results.

@JP  
So it’s best to re-validate the certificate as soon as this site resolves it’s problem before I get problems with the certificate?

@SeraphimDawn  
Yes, once the situation clears, go back and re-check the OCSP setting. It’s a global setting, it disables the validation on every HTTPS site, not just Derpi.