There may couple of reasons
- It might be a graphic card issue (see if it is recommended by SW and proper drivers)
- Geometry error (try a geometry analysis and see if any errors)
You were right, there was a geometry problem, but I can not tell why.
I went back and forth with my the "feature bar" and I found where the problem was, it was a "cut" operation. I went to the sketch, edited the plane (deleted the face where it was I selected the same face) and it worked. It is strange because I didn't really change anything in my part, but it worked.
Try clicking on a drawing view and changing its display style (Hidden Lines Showing, Hidden Lines Removed, Shaded with Lines, etc.) to see if that will bring it back. If it does, then switch back to the style you want.
Looks like a geometry or graphics card issue.
On drawing, right click on view and select show. Sometime this helps.
I have seen the same issue. Sheetmetal parts with faces missing. This is a big issue if you have it built into a large assembly since assembly drawing views get stuck in "draft mode" for every drawing view that references these parts in some way. You need to do a check feature search in order to find them. Moving the feature bar all the way back and down again combined with a force-rebuild can resolve the issue. Sometimes you need to revert back to a back-up copy to fix the problem. I have seen it predominately with sheetmetal parts but not exclusively. In all cases it was not graphic related. It actually was the part itself. No guaranteed fix for this issue. Happens at random for what I can tell in my line of work. Usually the parts are simple in nature.
That's all I can say.