Hi guys.. This is the MOST annoying bug I had in Autocad 2012-13-14 and 15. Never found any thread about that. Hope you guys can help.In layout, I have a viewport, The vieport model is in Conceptual visual mode, and contain about 30 layers. Some of them are VP frozen, some are VP Thawed. A very normal scenario.When I save or the Autosave happen, all my layers gets visible! The visual proble get fix as soon as I switch ON or OFF any VP Freeze in the model. It sort of refreshing it.When you have many layout with many viewport, it's getting sometime very very frustrating to work with that bug. Fortunatly, it's only happen when I work in 3D (Conceptual). Wich I try to avoid at all price. When I got my cad2015 and realised the bug it still not fixed, it seriously make me think of finding a defentive alternative to autocad in term of 3D modeling.By the way, a redraw or regen all doesn't do anything!thanks for your help.

It's not a bug.