ASP.Net Web Application Add Config Transform Grayed Out

Solution 1:

You must first define the configurations in the Configuration Manager. To be sure you are bringing up the Configuration Manager, you can access it by going to: Build->Configuraton Manager

In the Active Solution Configuration dropdown, select <New...>. Once you've added, you will then be able to "Add Config Transform".

Don't edit your solution file directly. It will only cause headaches.

Solution 2:

As we work with PublishProfiles, for me the answer was right-clicking the relevant pubxml file (found in the project folder Properties subfolder PublishProfiles) and then selecting Add Config Transform. No managers needed ;).