Unlikely Script Error with Matrix4x4.TRS

This piece of code gives the errors:

 GUI.matrix = Matrix4x4.TRS( Vector3.zero, Quaternion.identity, Vector3( (float)Screen.width / nativeWidth, (float)Screen.height / nativeHeight, 1f) );

" Assets/Scripts/UI-MAP/GUIMain.cs(46,40): error CS1503: Argument #3' cannot convert object' expression to type UnityEngine.Vector3'" "Assets/Scripts/UI-MAP/GUIMain.cs(46,80): error CS0119: Expression denotes a type', where a variable', value' or `method group' was expected"

Whereas this one doesn't: I couldn't figure what this is about, hope you can help me thanks.

 float rx = (float)Screen.width / nativeWidth;
 
 float ry = (float)Screen.height / nativeHeight;
 
 Vector3 vect = new Vector3(rx, ry, 1f);
 
  GUI.matrix = Matrix4x4.TRS( Vector3.zero, Quaternion.identity, vect );