Simple cloth crash

Hi,

I want to set a metal cloth and I managed to do it with mesh "cube.1m.mesh".
but with my own mesh created in blender I did not managed to launch my game. (a simple sphere)
I use NxOgre 0.9

Crash occured in NxClothMesh* Cloth::__createClothMeshFromOgreMesh(const NxString& name, const NxString& meshName)
at this line 428 in nxOgreCloth.cpp:
const Ogre::VertexElement* posElem = vertex_data->vertexDeclaration->findElementBySemantic(Ogre::VES_TEXTURE_COORDINATES);

posElem == NULL.

What I forgot in blender??

note: My mesh can be render in game.

i have an error in exporter log: bounds not completly defined.

I do not know what means that error.

Does the mesh have texture co-ords?

In my original cloth code the mesh has to have texture co-ords.

In blender I add an icoSphere and I apply a material without texture(jpg, png...)

I think mesh have no texture coords.

Edit: I try with an UVsphere and error when exporting mesh disapear but no text coord can be get in nxogre code.