When you try add new item from BizTalk project, following is what you normally see

However when something went wrong, you only see a few items in it or doesn’t see at all. Environment above was Visual Studio 2013 Update 5 but this problem existed from old days.

The easist way to fix is excuting following commands from Visual Studio’s bin directory.

devenv.com /resetskippkgs

If problem still exists, remove Developer Tools and SDK from BizTalk install and add it again.