unity3d bug all objects bad position in the scene after updating unity

Hi, is anyone getting this bug?
I'm loading an old project with the last version of unity.
After updating the project, lots of game objects get their position reset. as example, all the trees are now in the same position that the first instance.
Same for the ground position that has changed. lots of walls get their rotation and position reset. some animation don't appear in some gameobject.
I have to move lots of things to the correct position. almost a week of work. anyone has a solution?

Thanks

 

Hellooo?? anyone help??