Cannot attach Visual Studio 2015 to Unity 5.3.2

I am trying to debug my game in Visual Studio 2015, but the “attach to unity” button has been replaced with “start”. I have tried to delete all the folders but Assets and ProjectSettings but nothing happens. The problem occurs even when I try to create a brand new project. Is this a known bug? As I recall, the debugging works fine with a previous version of Unity.

EDIT: Attach to Unity is working properly in my laptop running version 5.3.3f1.

Updating Unity to the latest version (5.3.4f1) did the trick.

I was having the same problem with Unity 5.3.5p2

It’s a fresh install, I first removed all versions of Unity and Visual Studio, then installed Unity. revolute’s comment also doesn’t work; installing that Unity extension does not work; after running the installer, it is not listed in Visual Studio under Tools > Extensions and Updates.

The solution in my case was to first remove the extension, then add it again.