iCloud calendar not working

At work I use iCloud.com to manage my calendar. I do not want iCloud for Windows because I don't want my personal calendar information shared on my networked work computer. I also don't like using Outlook. I like using the website for my calendar. Within the past 3-4 weeks, after logging on to iCloud.com, I click the Calendar icon and get the error: Can't load calendar, there was a problem loading the application.

Every time this happens, I click Report and get this pop up:

I called Apple Support last week, and while the person was nice, it was evident he was stumped, too. I cannot be the only person in the world this is happening to, can I?

Thanks in advance - Amy