1067: Implicit Coercion of a value - actionscript

Question

So I'm currently trying to run my collision test on my two sprites, and I'm getting the following error:
C:\\Code\\Game\Game.as, Line 54, Column 34 1067: Implicit coercion of a value of type mvc:PlayerModel to an unrelated type assets.Scripts:SpriteAnimation.
Which is pointing to the following line of code:
handleSpriteToSpriteCollision(_player, _boss);
The function is as follows:
private function handleSpriteToSpriteCollision(sprite1:SpriteAnimation, sprite2:SpriteAnimation):void
{
var toSprite2 : VectorModel = new
VectorModel(0,0,0,0, sprite2.x - sprite1.x, sprite2.y - sprite1.y);
var bitmapData1:BitmapData = new BitmapData(sprite1.width, sprite1.height);
while(testBitmapCollision(sprite1.spriteFrameBitmapData, sprite1.topLeftX, sprite1.topLeftY, sprite2.spriteFrameBitmapData, sprite2.topLeftX, sprite2.topLeftY))
{
sprite2.x -= toSprite2.dx;
sprite2.y -= toSprite2.dy;
}
}
Both sprites display just fine, but as soon as I make the function call it all comes crumbling down. At this point I just need some fresh eyes to take a look at the code to see what's going wrong.
Edit: Here is the PlayerModel.as
package mvc
{
import flash.events.Event;
import flash.events.EventDispatcher;
import assets.Scripts.SpriteAnimation;
public class PlayerModel extends EventDispatcher
{
private var _previousX:Number = 0;
private var _previousY:Number = 0;
private var _xPos:Number = 0;
private var _yPos:Number = 0;
public var vx:Number = 0;
public var vy:Number = 0;
private var _height:uint = 30;
private var _width:uint;
private var _color:uint;
public function PlayerModel():void
{
}
public function update():void
{
xPos += vx;
yPos += vy;
}
public function get height():uint
{
return _height;
}
public function get color():uint
{
return _color;
}
public function get xPos():Number
{
return _xPos;
}
public function set xPos(value:Number):void
{
_xPos = value;
dispatchEvent(new Event(Event.CHANGE));
}
public function get yPos():Number
{
return _yPos;
}
public function set yPos(value:Number):void
{
_yPos = value;
dispatchEvent(new Event(Event.CHANGE));
}
public function set setX(value:Number):void
{
_previousX = value - vx;
xPos = value;
}
public function set setY(value:Number):void
{
_previousY = value - vy;
yPos = value;
}
}
}

Answer 1

The first thing i would check is the class of your boss and player objects inherit your SpriteAnimation class:
class PlayerModel extends SpriteAnimation
{ ...
Seems as though your handleSpriteToSpriteCollision function is looking for two SpriteAnimations and at least the PlayerModel being passed isn't one
Sprite inherits EventDispatcher so as long as your SpriteAnimation inherits Sprite as well, you shouldn't lose any functionality