Visual Studio 2015: Git Diff Tool Window is empty

Question

I am using Microsoft Visual Studio Community 2015 (Version 14.0.23107.0) and Visual Studio Online with Git. When I right click on a file in Solution Explorer and select "Compare with Unmodified", a new Window opens, which is empty. The Tab on top of the editor window is on the right side. When I hover the mouse over it, it says: "Preview of: Filename", while there is still a tab on the left for the original window "Filename".

In Team Explorer, Settings, Git, Global Settings it says: Diff Tool: Visual Studio | GLobal

It says the same in Repository Settings

I remember that some time ago I could make here a selection and I clicked on "Visual Studio". Now it is read only.

I get the same empty window when I try to investigate a merge conflict or when I try to see how a file in a commit has changed "Compare with Previous ...".

What do I need to do to get the Diff Tool work properly ?

Answer 1

It's a bug that happens when you have the option "Enter outlining mode when files open" disabled (it's in "Tools -> Options -> Text Editor -> C# -> Advanced" ). Until it's fixed, enabling that option should make the diff tool work again.

See the answer from Chris S. Nissen here: https://social.msdn.microsoft.com/Forums/vstudio/en-US/00bb6e4e-1e3c-40e4-ba09-479d67e622e2/blank-compare-window-in-vs-2015-rc-for-c-files?forum=tfsversioncontrol