Visual Studio 2015 Git "Failed to start the configured compare tool."

I wanted to run a diff on a file in my project which should be a simple task, and when I select Compare with Unmodified, I get the error:

Source Control - Git
Failed to start the configured compare tool.

I've looked at the .gitconfig file that was auto-generated by VS2015 and as far as I can tell there is nothing wrong with it.

[merge]
    tool = vsdiffmerge
[diff]
    tool = vsdiffmerge
[core]
    editor = \"C:/Program Files (x86)/GitExtensions/GitExtensions.exe\" fileeditor
    autocrlf = true
[credential]
[filter "lfs"]
    clean = git-lfs clean %f
    smudge = git-lfs smudge %f
    required = true
[difftool]
    prompt = false
[difftool "vsdiffmerge"]
    cmd = \"C:\\Program Files (x86)\\Microsoft Visual Studio 14.0\\Common7\\IDE\\vsdiffmerge.exe\" \"$LOCAL\" \"$REMOTE\" //t
[difftool "vsdiffmerge"]
    keepbackup = false
[mergetool]
    prompt = false
[mergetool "vsdiffmerge"]
    cmd = \"C:\\Program Files (x86)\\Microsoft Visual Studio 14.0\\Common7\\IDE\\vsdiffmerge.exe\" \"$REMOTE\" \"$LOCAL\" \"$BASE\" \"$MERGED\" //m
trustexitcode = true

Any thoughts?

Solution

Uninstall all versions of Git on the machine and reinstall the version needed. Seemed to work for me.