I have a issue with the extension soap skin & bubble - for some unknown reason it creates extra unwanted lines. I have tried uninstalling and reinstalling sketchup and the extension, and it is isolated to a single user. (who has just changed computers and it has followed along?!)
I also have tried upgrade to pro for a trial period, but still no difference
33.skp (936.0 KB)
Thanks, @DaveR. File attached.
I am aware that the author is not particularly active on this forum, but it seemed to be my best chance.
As an alternative, we are using Curviloft, but sometimes old habits die hard, and some people struggle to change.
I just ran it with your model. After removing the straight lines and welding the segments in the curves on each side, it worked fine for me with 24 divisions. No bug here. When you were running it, were your curves welded or exploded?