i'm having a similar issue- tried everything in the manual. lofts, extrudes etc. in a variety of formats from curves to polys and nothing seems to work. it keeps telling me there's something wrong with the path/profile or just that it can't do it at all- what i need to know is exactly *why* it isn't working, but it doesn't tell you that!
strange thing is: i have managed to get it to work before and i haven't done anything different... at least i don't think i have... yet it now isn't working! anyone got any ideas?