Same thing here!
been trying to access MyCIC since last Friday 14/9/2016 with no luck. Right after logged in and when clicked on "Continue" it gives me "Internal Server Error 500".
I cleared my cached files, changed browsers, changed device, even changed internet connection and the same error still comes up every time!
Also submitted a CSE with Technical Difficulties. Still, nada!
The most annoying thing is, I received an email from CIC yesterday and can't even view the update on my application because of that 500 Error.
Any solutions apart from creating a new CGKey and linking it to your App?