Occasionally I'll get a generic sort of warning regarding the system family I'm trying to make, telling me "Sorry Steve, I can't make this thing for you".Regardless the error message could certainly be written better; to mention that such an error may be related to a profile that isn't created properly. At this time, the error trapping process may not be able to reach deeply enough into the sketch mode process, for example like we use to create a Floor Slab Edge. Regardless, there is no reason the error message couldn't mention a common culprit, something to prod us to look more deeply for.
Quite often the reason Revit is complaining is because I was sloppy making the Profile family. You may recall I've written about good sketches and bad sketches in the past.
Technically the error is in a component family and then evaluated as part of a system family that references it. In a sense it is too far removed from the active operation for Revit to properly recognize what's wrong precisely. Therefore I think it would help if, while saving a profile family type, Revit tested it for proper closed boundaries to help us catch errors while editing the family. Revit does this when we attempt to finish a sketch for a solid or void form. Perhaps it could be a button on the ribbon? Something like Test Profile.
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