isKinematic = false makes unity executable crash

Its exactly the line with "is$$anonymous$$inematic = false" that crashes. Precisely that line.

 var radius = 5.0;
 var power = 10.0;
 function Start () {
     // Applies an explosion force to all nearby rigidbodies
     var explosionPos : Vector3 = transform.position;
     var colliders : Collider[] = Physics.OverlapSphere (explosionPos, radius);
     var colliders$$anonymous$$inematic : Collider[] = Physics.OverlapSphere (explosionPos, radius/8);
     
     for (var hit : Collider in colliders$$anonymous$$inematic) {
         if (hit && hit.rigidbody){
             hit.rigidbody.is$$anonymous$$inematic = false; // RIGHT HERE
         }
     }
     for (var hit : Collider in colliders) {
         if (hit && hit.rigidbody){
             hit.rigidbody.AddExplosionForce(power, explosionPos, radius, 3.0);
         }
     }
     
 
 }

Ah ok. Like I said, I've never encountered this specifically. Why are you disabling the physics? What you've done seems like it should work in theory, but in several physics engines I've had issues with turning physics on and off so usually I have either two copies of the object for things like allowing user dragging AND physics or I coerce physics into doing what I want such as using force to achieve what I want to do by turning physics off.

Well what I have is a house with frozen chunks (Physics disabled). When an explosion is set upon the house, the physics of chunks around a certain radius of the explosion are turned on and then applied a force to send them flying. Like I said, it works fine in the editor. But in the executable it just gives me that annoying Access Violation. I tried disabling them in another way, like constraining them while leaving the physics on but it starts lagging terribly.

Just some thoughts. You might want to move your code to a FixedUpdate handler ins$$anonymous$$d of Start. Physics behaviors work better in fixed update and sometimes hicky things can happen in Start functions/first frame like from not everything being really initialized.

The other thing you could do is build your house with non-rigidboy chunks and then swap them at explosion time with rigid body versions using moveTo and then explode away.

Quite an old version of Unity, because it's quite an old question...