Master Model part failure - "The Base Part Has No Solid"

Hi All

I've created a Master model to create the overall shape of a plastic enclosure, then used Split feature to save off front and rear halves.  Then added all the necessary detail to the two halves in their individual part files.  And made an assembly from those part files.

Then, in one of the halve's part file, I created a new configuration.  Clicked the default configuration, Control-C, then Control-V.  When I hit Control-Q, all the features turn red.  The very first feature (where the part was pulled from the master model) gives the error "The Base Part Has No Solid."

I've attached some pix.  Does anyone have any idea what that means, what's caused this, or how to fix it?

Actually, now even the default configuration is doing this, and "Reload" does not solve it

Closed everything, Re-booted SolidWorks.  The part comes in ok, with all features intact.  Soon as I hit Control-Q, it is destroyed.

Tried this on the rear half, and it still works fine even after creating a new config and hitting Control-Q.

When I "List External References" on the failed first feature, it points back to the master model, and says

Data               Status                             Referenced Entity

Solid Body     In context                         Solid Body of Part A(master)

Feature          In context                          Split 1 of Part A(master)

Very confused and would appreciate any insights.

SolidworksPlastics And Mold Design