With CCSv4, this always worked, but it has NEVER worked with any v.5.1 candidate I have installed. (I started using CCSv.5.1 at M5.)
With every new release, SYS/BIOS (and other components) get upgraded which make my project settings stale (since I don't copy over the old versions to the new install directory):

I have nine different build configurations, so changing these one-by-one for each is a royal pain. In CCSv4, I was able to click on the top-level project branch and choose "Refactor-->Upgrade RTSC Project Versions...," and I could upgrade all the configurations at once. In CCSv5.1, though, the only thing it allows me to upgrade is the XDCtools, and the RTSC Project listings are always blank:

