Commented out an alpha-3 incompatible change. revert this commit afterwards.

jme3-core/src/com/jme3/gde/core/sceneexplorer/nodes/JmeMotionPath.java

@@ -294,7 +294,7 @@ public class JmeMotionPath extends AbstractSceneExplorerNode {
 
         Material m = new Material(SceneApplication.getApplication().getAssetManager(), "Common/MatDefs/Misc/Unshaded.j3md");
         m.setColor("Color", ColorRGBA.Red);
-        m.getAdditionalRenderState().setLineWidth(4f);
+        // Alpha4: m.getAdditionalRenderState().setLineWidth(4f);
 
         switch (motionPath.getPathSplineType()) {
             case CatmullRom: