Hi!
Literally just trying to split a line and no matter what I do it keeps saying the lines don’t intersect. I’ve tried make 2D about 5 times already.
Here’s the file:
Example.3dm (182.9 KB)
Thanks 
This seems to work, however the result after the split is grouped so I ungrouped it.
Example.3dm (217.7 KB)
i can see the same issue, it does not work for me, also somehow you managed to group the separate parts prior to joining and after exploding they still are grouped… anyway after exploding and ungrouping it splits.
that it does not split seems a bug to me.
What doesn’t split?
that exact part which you managed to split, with that tiny line i assume. that only works when i explode and ungroup. in that state as it is it fails with some tolerance comment.
Hello - the file as posted has a closed curve and one object that could split it as far as I can see - a closed curve cannot be split at one location, you need at least two.
-Pascal
The curve is grouped in a group of one.
The split works fine (with the two tiny line segments), but it appears to fail because the objects stay grouped.
Ungroup the result and you have 2 curves.
There are two small lines to split the curve. In the file in my reply above you can see the two curves on a separate layer