Abbreviate Qualified Package Names not working?

Hi,  i'm on 

IntelliJ IDEA 2016.3.2
Build #IU-163.10154.41, built on December 21, 2016

I'm a big fan of "Abbreviate Qualified Package Names" but it seems not to be working in this release.  In the Project window, I select "Flatten Packages" and the selection appears.  However, selecting it does not do anything.  It remains unselected and the package names remain unabbreviated.