I am always getting errors when working with solids. It drives me crazy sometimes, because I get a message that says "Failed in Boolean Operation" or "At least one surface cannot be unstitched", or some others, but there is no information about why I got the error or what happened. I have to examine the surfaces very closely, and sometimes move them up or down or sometimes recreate new surfaces to work with.
I really wish the BCC fairy would give me some yellow sticky notes with information about what is wrong with my surfaces.
Jim