I can't select an edge. Selection filters isn't the issue.

See for yourself. When you edit Surface-Loft21, select the Open Group <3>. The line that is co-linear with the purple short line cannot be selected.
bottom of side skirt.png

Interesting… it seem like surface trim 38 is causing the issue? I tried it on my end and seem like it only happen after trim-38.
Maybe a bad vertex/edge?

A little trick i learnt in the past, you can try to copy the two surface (offset=0) and try to re-select the edges using the offset surface again and it may just work
image.png

You’re right Zhen, the edge can’t be selected after that trim 38 even though nothing was trimmed in that area. Very odd. I initially did the offset of 0 but that seemed to cause issues later when trying to knit and create a solid from this. I think its because the loft with the problem edge is a child of other surfaces and when I do an offset and create geometry from it, this creates 2 different sets of dependencies.

..something goes south after Surface-Trim38.
..rollback to that and dissect. All the trim’s create inaccuracies.
I personally think you are doing too many trim/knit’s early on.

..here’s a workaround.. create a compcurve before Surface-Trim38
Screenshot 2022-03-19 204351.jpg

That’s a great workaround. Thanks, that worked! I didn’t even know you could create a comp curve from surface edges. I only think of it as a tool to join sketches.