VERY THANKS Michael

I use "Weld vertices alone edges" ON, "N-gones" to OBJ not good
I use "Weld vertices alone edges" OFF, "N-gones" to OBJ not good
I use "Weld vertices alone edges" ON, "Quads& TRiangles" to OBJ good but I don't like the Triangle faces---
I use "Weld vertices alone edges" OFF, "Quads& TRiangles" to OBJ good but I don't like the Triangle faces---

USE FBX is all OK---- Thanks-- I Learned more--

Hi qibentie, you're welcome, I'm glad that you have a good solution with FBX now!

It looks like Max's OBJ importer just is not able to handle complex n-gon shapes.

I don't know why, but Autodesk did not seem to make any effort on improving their OBJ importer for many many years. But they have been active in improving the FBX importer. That's specifically why I added FBX export support to MoI, since Max just does not seem to do a very good job with their importers for other formats.

- Michael

so it was FBX + Ngones ?