itch.io

It works!

The cause is that my way to make prefab.  

I made prefab that has no parent.

Now I make prefab that has parent.

And I make my Stage.

When I erase one of object in the stage, It works that only one object are deleted.

This is that I hope.

Thank you very much for your answer. That helps me.

And thank you for giving a great Asset. 

I made an original prefab to load prefab into MAST.

And I've  made my stage.

When I use eraser, all of object in the scene are deleted.

If I want to erase any object  by using original prefab in MAST, I have to click the object and delete one by one?