Publishing Visual Studio 2017 multi-project VSIX to the marketplace

Question

I'm trying to port my Extended Visio Template visual studio extension (multi-project template with custom wizard) to Visual Studio 2017.

I followed the steps for migrating extension, as clarified in the documentation: https://docs.microsoft.com/en-us/visualstudio/extensibility/how-to-migrate-extensibility-projects-to-visual-studio-2017

It builds and installs/works locally fine ("works on my machine") but the visual studio site refuses to accept it, giving dumb error message Invalid Template File in VSIX. May it be connected somehow to recent migration of "visual studio gallery" into marketplace (does it work at all) - is it me, or them? :)

Should I do something differently for VS 2017, if it's a multi-project template (the multi-project template for 2010-2015 seems to upload fine)?

Or maybe somebody can give me a link/reference to a working source code for multi-project template for Visual Studio 2017 (v3), that can be successfully uploaded to visual studio gallery?

Full source code is available on github, including manifest, and all templates (files with .2017 suffix)

Answer 1

Answering myself, for those who may fall into the same trap :) The problem appeared to be missing <Icon> element in one of the child projects.

After Microsoft migrated the gallery hub to Marketplace, it started go give you much better diagnostics on failures, helping to address those sort of things - now at least it is possible to figure out what the marketplace didn't like in your extension exactly :)

After adding <Icon> the extension was successfully published