Has anyone else run into this problem?  I have come up empty trying to find out what this means.  My process was building fine until now.  What I suspect caused the problem was a "feature" I stumbled over (and now can't find) -- I was right-clicking on various objects in the process when I saw some menu-items I have never seen before.  The options were a bunch of "Override [INSERT ITEM NAME]" like "Override Save", where save is an Action.  Anyway, they looked very interesting so I clicked on one of them (oohhh!  Shiny!).  Bad idea.  Visual Studio's memory consumption went through the roof, a whole bunch of errors were generated, and then Studio crashed.  Ever since that happened I can no longer build my process.  If this is not a known issue (which it does not appear to be) then I will submit a ticket.

I hazard a guess the menu options I came across maybe are related to features that are currently hidden because they are buggy.   Somehow they got displayed, and I couldn't resist the temptation to explore.  They seemed innocuous enough.