I have created a internal part, which has a few configurations, then I created a drawing for each of configuration for the part, the strange thing happens when I open the drawing later. The vitual drawing were gone and left a blank box with x on it. I just experience this  recently, so I called Solidworks tech supporter to figout what the problem is, the tech supporter told me I can not create drawing for an internal part? Is that true? I never heard of this before, I created drawings for internal parts before, I have never have the problelm.

My question is is that true that I can not create drawings for an internal parts, if it is not true, does  anyone know how to solve the problem.

Thanks

Andrew