I have two emitter particle brushes. I had one canvas (icosphere) and both brushes could paint on it. I wanted a second icosphere that was identical to the first - and have both brushes able to paint on it - however, when I duplicated the sphere - It crashed on render. When I deleted the second sphere - it rendered fine. So I created a second sphere - from scratch - created a new canvas - tried to render - crash again.
I know I'm missing something - tried creating a separate material with vertex paint - tried changing paint map - no dice. I know I'm missing something.