As it turns out, this was trivial. When I installed to IIS originally, I used the Web Platform Installer. It created an Application Pool for the installation and set the target framework to .NET 4. When I set up the dev system, I installed from the source package and neglected to properly set the framework version for the application pool. The default was .NET 2.x. After making the change from v2.x to v4 in IIS Manager, the lights came on.
For anyone who comes across this post with the same issue, do the following:
1. Start the IIS Manager
2. From the Connections Pane on the left, expand the server node and then click Application Pools..
3. In the right pane (Application Pools) double-click on the application pool to which you have the application assigned.
4. From the .NET Framework Version dropdown, select .NET Framework v4.
I know this step was documented prior to this post. My appologies and thanks for a great CMS.