Hello, I am receiving tons of errors with my build(and 1 ingame) I do not know what they mean, so, can someone please help me? Thanks. 
bump ?
The “tensor of inertia” error occurs when you try to use a rigidbody with a mesh collider that is not a completely enclosed volume. This typically happens with a plane or with an object that has a “hole” or an open side. The easiest way to fix it with a plane is to remove the default mesh collider and replace it with a thin box collider. If the object is more complicated then the hole may be a mistake in the geometry that you can fix. However, if the open part of the mesh is intentional then you will need to set the tensor of inertia yourself. The tensor is essentially a vector where the X, Y and Z components represent how hard it is to start the object rotating around each of the three axes (eg, a large value in the X component means that it is hard to rotate the object around the X axis).
The “script missing” errors can sometimes happen if you move the project or files within it from the desktop rather than within Unity but there may be other reasons. The affected objects will say have a MonoBehaviour component attached but it will say that the script is “missing”. This generally doesn’t mean that the script file has been removed from the project but just that it is not found at the place Unity expects. You can select the script you want from the popup menu on the MonoBehaviour component. However, if you have many objects with this problem then you might find it easier to revert to a backup copy of the project if one is available.