We have an issue with Microvellum OEM 2019 with 3D solids disappearing from the drawing. It seems to happen randomly. For example, we would save a drawing at the end of the day and everything is good. But the next morning, when we open the same drawing, all the 3D solids have disappeared. There is no error message. Both AutoCAD and Microvellum created 3D solids would be gone. The Microvellum 2D products are not affected.  Fortunately, the Microvellum products Item Numbers are still there and we could re-draw them in 3D. But the AutoCAD extruded 3D solids are gone completely and it is a nuisance to re-draw and re-extrude all the AutoCAD 3D solids. Sometimes only the Microvellum 3D products disappear and in this case, usually closing and re-opening Microvellum works. It seems to be happening to 1 user more than others in the office.