Inventor files are made of 6 discrete segments. I don't recal exactly what they all are but brep data, graphics data, parametric data etc. would be the general idea. I suspect your error message indicates IV can't access one of these segments. I would guess your only possible solutions are resort to an old version from the old versions folder, delete the view and recreate it, or recreate the drawing. Certainly not the answer you were hoping for. If you have to recreate the drawing make sure you can create views, save, and reopen OK before you do all the annotations. It would REALLY SUCK if you redid the drawing and ended up with the same problem because it was a problem with the assembly or parts all along.