Trouble accessing a site on a Mac

I am an "network administrator" (i use this term very loosely, just part of my job) for my company and part of my responsibility is to sign up new employees on a website to do training. This is something I had always done from home. I was able to sign on the site with my Macbook Air with no problems for a year, at least. In the last month, I have not been able to access the site at all. It just starts loading and doesnt do anything. I also cannot pull it up on my Iphone, Ipad, or old Macbook Pro, which I had no problem doing in the past (save the Apple jokes )

I can log on to a PC and access it with no problem.


I sent an email to corporate who has been "working on it" for the last month. They are generally clueless, so i was hoping someone may have an idea on what my problem is? It's a huge pain in the arse for me.