Why does CodeLens always show "0 authors, 0 changes"?

I came across the same issue in VS 2017. The fix was to change "Changes in months" field. If you left click on "0 authors, 0 changes" link, a pop up will appear. It has a field in the bottom right corner which you could adjust. I changed it from 12 months to 48 months. The change was automatically applied to the whole solution.

I had the same problem. Tried re-installing GIT, etc. Finally, I decided to uninstall and reinstall VS 2015 with update 1, and that corrected the issue.

Visual Studio 2015 Update 2 fixed my problem.

https://www.visualstudio.com/en-us/news/vs2015-update2-vs.aspx