Carol, it might be that the drawing was accidentally set to a tilted Z plane, or possibly a setting in the drawing. You can also try setting VISRETAIN to 1. That setting being set to zero usually causes strange errors like that.

Otherwise, I'd need to see the DWG file to help troubleshoot more. If you're an F/X CAD user, you can submit a ticket for this CAD issue. Otherwise it'd be best to reach out to your AutoCAD support.

Here's some AutoCAD support pages I found that could give some clues:
Mouse cursor or crosshair disappears in AutoCAD products

Forum: Cursor disappears when selecting objects

-Amanda