As I recall it's a little tricky to get VPMage to build stuff. Here: step-by-step tutorial.
#1. Arrange files you want in a VP into their proper folders (music, models, effects, etc.) and place all of those folder in a folder called "data".
#2.Open VPMage, go to top bar and click "dir". Find your data folder and select it. Now click "add source". That folder should appear in the right hand window.
#3. Go to bottom bar. Click "file" and name your vp. The name MUST have ".vp" at the end of it. Example: "Echoes.vp"
#4. Hit "Build VP". No progress bar will appear, but be assured that VPMage is working. Depending on how large the file you're building is, it will eventually say "VP Created".
#5. Enjoy the freshly built VP file!