Hi Klingbeil, if I select some pieces, they show up as a solid in the "Type" indicator in the upper-right area of the window:



It's a degenerate solid though, with just 2 faces joined to each other making a kind of flat pancake with no area inside of it.

So my guess is that you had some duplication in your pattern with at least 2 faces stacked up in the same area, and you're getting those duplicates joining to one another instead of joining to their neighbors like you want.

You'll need to make sure you don't have any exactly-stacked-up duplicates in the pattern before you join it.

- Michael

EDIT: Burr wins this time! ;)