Sometimes SURFPATCH will not patch - Modeling Operation Error

[Anonymous]

64 bit SP 1.1 applied

Some of the 3D poly-lines refuse to be 'patched' using SURFPATCH (attached DWG)

Command resultis in this message:

Modeling Operation Error:
Operation unsuccessful.

Cannot create patch surface from the selected curves.

In the attached DWG, the thinner middle 3D poly does not become a surface using SURFPATCH, can anyone explain why, what is invalid in the 3D poly?

TIA,

Kevin.

[JDMather · Accepted solution]

Is there any reason you can't do as 4 curves (actually only need 2) and Loft instead?

[Anonymous]

Thx JD ... removed the end segments and used LOFT

would still like to have a more detailed message from acad explaining what was invalid

Thx again

Kevin.