Hair curves (fur) transfer - now wrong interpolation 4.2.13

Hello. I transfered modifiers (ctrl+L) between fur-Assets. Both the mesh and the curves where different.
I removed all referals to the old mesh, where possible.

But there are still 3 problems with that.
One can be seen in the screenshot: hair interpolation is a mess.


The second one:
When placing a new haircurve in certain places around the back of the model: They don’t interpolate length and shape correctly - they also dont snap to the surface when i am in hair sculpt mode in certain areas.

modifiers of the hair:


For testing purposes, I deleted all other modifiers. no difference.

hair curve attributes:

“B_Body” is correct, “UVMap” is also correct.
“B_Body” contains no animation data or shape keys.
UVMap is a clean, new UV with no overlaps.

Any ideas what is missing?

Even When I remake the interpolate modifier, it still messes up.

i stumbled upon something - finally i found an error message.

I created the modifier “surface deform” - it had more than 4000 “invalid surface UVs on curves”.

I reparented the hair curves (Ctrl +P) and attached them to the body. I was left with 56 invalid surface UVs. This was good enough to fix all wrong interpolations.

But I will take care of the last wrong hairs.