It seems that I had references to the incorrect versions of the dlls I needed; it compiled just fine but wouldn't run properly.
Rather than search through C:\ to find the dlls necessary as suggested on another site, I found the four Microsoft assemblies I needed in Reference Manager > Assemblies > Framework
Microsoft.Build.Framework
Microsoft.Build.Utilities.v4.0
Microsoft.TeamFoundation.Build.Client
Microsoft.TeamFoundation.Build.Workflow
This ended up fixing my problem, and the config file is now being transformed as needed