'Surface Intersection Error' during Boolean Union (Help!)

booleanring.3dm (4.8 MB)

Hi all, newbie here. I created a ring with an SVG curve I imported and extruded, then used flow to warp it around a ring. Now I tried union, and the boolean union failed, the exclamation marks read ‘surface intersection error’. What can I do to fix this?

Make sure the geo you are flowing intersects the thing you want to Boolean too, it won’t work if its just riding along it.