Hello - this is a problem, occasionally, with Flow/FlowAlongSrf that I’ve encountered a bit more than I like lately - the flowed surfaces are refit to a fairly dense structure and the control points tend to get jumbled - the surfaces that start off vertical end up folding on themselves at a microscopic level.
Here, I moved one point slightly out of line so you can see the fold/overlap at the surface edge (arrow)
On this object, to get your work done, you can do the following and it should work:
Explode the flowed part.
- Select all the side, or vertical surfaces
FitSrf to .001, DeleteInput=Yes. This will remove a lot of control points and return a thing that is, hopefully, slightly simpler and not folded.
Join and Join to the top and bottom surface.
- Boolean operation.
I don’t know if there is anything we can do to make this more reliable for small objects like this but I’ll try to corner a developer and see what he thinks.