3 suggestions:
1) Go to the top menu bar, and under View, click "Hidden Geometry." It is possible you may have hidden an element, group or component in the making of your model, and may have forgotten about it. The Hidden Geometry option will reveal any invisible edge with broken lines, and any invisible texture with grid-lines.
2) Go to the Components window, click on the house icon ("In Model") for a list of components in your project, and see if any of them look blank and empty. If such a component serves no purpose whatsoever in supporting the model, you might as well delete it.
3) It's also likely that at some some point before sharing a model, you would have been shown the option of purging unwanted items that don't show, but declined to do so. It's always best to take care of that in advance, by opening up the "Model Info" window.
- jago716