Save from "founding durotar" campaign

The save from founding durotar campaign is corrupted. When I start the campaign from the campaign list, (act 1) the model of misha and some other creatures, loads normally. The problem occurs when I save the game and load it. Then the model of Misha and some other monsters disappears. These units are then invisible, and you can only see the shadow beneath them. These units attack and can only be attacked using auto-attack. I can’t use skills on them or bypass them. I installed the latest warcraft 2.0.0. but I play no reforged yet. What can I do to play normally, to be able to save game and load it. It would be hard to play whole campaign without saves.