World collision problem

Help me out here! I’ve tried everything to put collision on the furniture in my 3D world but it won’t work.
I’ve tried to add physics to the furniture using the 3D model, I’ve tried using the Colíder and static boxes and nothing worked.

Might be years late for this. But to fix it, each object that have colliders must have a prefab. Make sure that prefab is included in the upload list when uploading to HighRise.