After hours of trouble-shooting with a 3rd level Apple technician, we finally concluded that there was something in my Internet Explorer that created this condition. Apple walked me through all kinds of troubleshooting - disabling Norton Anti-virus, deleting cookies, etc and all without success. Independently, I had downloaded Google's Chrome browser onto the laptop I was having issues with Internet Explorer, and my access issues to iCloud from this laptop went away. Apples explanation: check with Microsoft, it is their browser and Apple does not support it!!
However, my bigger - and original issue (as this "Can't load Calendar" was a new and additional issue) of iCloud not updating any of my Apple devices (iPhone 5, and iPod Touch) - is with Calendar events not being pushed from iCloud to my iPhone, and it still remains after a most recent two hour trouble-shooting session with Apple support. It's now been 3 weeks since this issue was sent to "Apple engineers"for them to investigate, with NO RESPONSE back from these "backed up" Apple engineers. With the latest trouble shooting, Apple support was able to isolate and prove that it isn't either of my Apple devices, but rather iCloud and my specific account. (We created a new iCloud test account that was able to update iCloud calendar events back to my iPhone real time). I've now turned my iCloud password over to Apple to investigate and fix my iCloud account issue - and have a follow-up call scheduled for Thursday November 15th. I am not holding my breath...