Help developing a new add-on

[VisioDeveloper]

But the latest released version is 3.10 (3.10.2)? At least I don't see a later one..?

Just checked again and i was downloading the weekly releases (not stable), I probably should of paid attention to that. My fault!

[Nikolay]

No problem, I'm glad it worked
As soon as WIX team releases the version, hopefully this bug with "references" will be gone.

BTW, I was able to reproduce the issue you wrote about before - if you don't build/save the solution and just create new and then close, then project file is broken (VSTO info gets removed).
Looks like some new bug-or-feature of VS2015 Update 1... Will try to update the extension to take care of that or if not possible try to rise an issue by MS..
For now, it looks that if you build/save the project at least once after creating and before closing, then all is fine.