Custom 3D Models Going Haywire on Building for Web

Hi,

I have just created some custom mesh of Walls and Floor in 3DS MAX and just Launched for web with medium scalability options.

Why do my meshes appear like a broken window pane ? Desktop builds just fine.
If I need to follow a particular method to make custom meshes for web build please advise how to proceed. Any reference links would help too.

Thank you,

Actual Mesh in Editor:

Actual Mesh Wireframe in Editor:

Improper Mesh in Web Launch:

Any help would be greatly appreciated…

Thanks