Thanks for your reply. But I figured out what I was doing wrong!!!
I learned a coding lesson the hard way. I had a bunch of includes in a header file, which I assume had all sorts of preprocessor commands that got mixed up with other ones… This is bad form, because includes should be placed into the cpp files, not headers, unless it is impossible otherwise.
While the errors have gone away in my code, I still cannot compile geant4_vmc.
I see this post,[url]Rootcint and ROOTSYS , but it is unclear what I should do.