For the record, this was all done on my local machine...
Since the exception shown above is somewhat cryptic (and turning on debugging in web.config didn't provide any further information), I decided to open up the website in Visual Studio and run the application in debug mode to see if this would garner more
information. I run the site in debug mode and low and behold the post page loaded just fine. Confused, I went back to the website (hosted on my local IIS) to verify that I was indeed still getting the exception and it was
gone there as well.
Long story short, I have no idea what happened but it seemed to resolve itself. It's possible that something I did reset IIS and maybe this fixed the problem. Maybe opening the site in Visual Studio caused a change which fixed the problem (doubtful).
I may have reset my machine and this somehow fixed the problem.
That's about all I have for you unfortuntaely...