m_Target variable missing

MissingReferenceException: The variable m_Target of ‘BoxColliderEditor’ doesn’t exist anymore.
You probably need to reassign the m_Target variable of the ‘BoxColliderEditor’ script in the inspector.
UnityEditor.BoxColliderEditor.OnEnable () (at C:/BuildAgent/work/842f9557127e852/Editor/Mono/Inspector/BoxColliderEditor.cs:22)

I am recieveing this error I just deleted the default 3rd person controllre model and I am
using a custom 3ds model and it compiles for the native editor game screen, but the game wont compile and build for other platforms. When i double click the error, it takes me to my charactercontroller script which has no reference to m_Target at all

m_Target is an internal variable, and by all means you should not be receiving that error.
It’s clearly related to a box collider, so for a test, I would create a new scene and try to replicate, this time -deleting- all box colliders on the scene progressively, to try and understand which one is causing issues.