Problem with box collider

in the scene i’ve a object that is the main object in the game… (with all script etc…)
if in this object i drag another object with box collider, the main object starts to move by itself… so i tried to remove the box collider from the object that i’ve added, and the problem is solved, but the box collider in that object is necessary for make a special things for the game… why box collider creates problems?

Are you sure your boxes don’t have rigidbodies on them? If you have multiple rigidbodies in the same hierarchy with colliders overlaping eachother problems like that may occur.