Options-> Tools -> External Sources ....doesn't exist!

Hi,

With Resharper, I used to use F12 to download a decompiled source & navigate into it..

For example - in C#, I could hit F12 on the DateTime class keyword, which would download decompiled source code & navigate into the class definition.

But recently I started using a new computer.  With a fresh install of VS2015 & Resharper Ultimate 17.1.1, this no longer works.  When I hit F12 I only see "DateTime [from metadata]"

Note that in my options menu: Resharper-> Options-> Tools -> External Sources ....doesn't exist.