This post will be a bit long because I have documented my recent attemped and failure to create a simple clothing item for LaFemme.

As you can see, I'm using the LF-QuickSuit HI.OBJ in Blender, directly out of the Poser Runtime, not the exported version.

Just to make sure, I checked for linked faces (Crlt+L)

I selected the upper half of the mesh and deleted the faces.

Once again I checked if the mesh is properly welded.

I deleted some more faces to have clean edges to the mesh.

Now I saved two OBJ's, on with "Write Normals" one without, just in case...

In Poser 12, I load the default LaFemme, disabled the IK and zeroed the figure...

Time to import the OBJ File or the Clothing Item. I unchecked all options in the import dialog.

Front and back are looking fine, no pokethroughs, no distortions...

The Fitting Room Simulation worked fine, both the Prop and the Figure are set to Zero. For Figure Creation I used the Settings above.
After the Figure was created, I looked for the skinning methode, Poser Unimesh was checked.
The Prop of the Clothing Item was deleted and the new Figure was conformed to LaFemme.
The conforming Figure follows along with LaFemme, the mesh fits perfectly...

...and if I bend the Shin, the mesh breakes and crumbles like so...                           ...and the side ways movement of the big toe splits the mesh...

I have tried everything I could think of to solve this riddle, changed import/export options in Blender/Poser for the OBJ File.
The pictures are done during the tenth try, I changed the program to create the mesh from C4Dr12 to the latest Blender version, I updated my nvidia driver yesterday, the Windows 10 version is two week old, every update is installed.
I studied the older Tutorials from Tony Vilters on YT and the once who are avaible here on Rendo.

I'm completly in the woods right now. Someone here have a clue?