Is there a tool in the Professional edition that will verify the site and let me know if there are problems? 

My first install failed when I used the app pool credentials for the file system permissions.  I changed the app pool and the file system to use the network service user and the install succeeded.

Thanks

Yes.

My 'Admissions' module is physically at: C:\websites\DNN6.2.1\DesktopModules\Admissions, where http://dnndev is mapped to C:\websites\DNN6.2.1.

I have tried opening the template-created .csproj at C:\websites\DNN6.2.1\DesktopModules\Admissions:

1. standalone in an empty IDE
2. double-clicking the .csproj to launch it in a fresh IDE.
3. as an existing project within an existing solution.
4. as a new project (with a location of C:\websites\DNN6.2.1\DesktopModules\Admissions to map to my existing DNN site)

All fail with the error at the root of this post.