Add boolean check for if paramters are showing.

Source/Editor/CustomEditors/Dedicated/AnimatedModelEditor.cs

@@ -14,6 +14,8 @@ namespace FlaxEditor.CustomEditors.Dedicated
     [CustomEditor(typeof(AnimatedModel)), DefaultEditor]
     public class AnimatedModelEditor : ActorEditor
     {
+        private bool _parametersAdded = false;
+
         /// <inheritdoc />
         public override void Initialize(LayoutElementsContainer layout)
         {
@@ -33,6 +35,7 @@ namespace FlaxEditor.CustomEditors.Dedicated
                                                     (instance, parameter, tag) => ((AnimatedModel)instance).GetParameterValue(parameter.Identifier),
                                                     (instance, value, parameter, tag) => ((AnimatedModel)instance).SetParameterValue(parameter.Identifier, value),
                                                     Values);
+                _parametersAdded = true;
             }
         }
 
@@ -42,12 +45,13 @@ namespace FlaxEditor.CustomEditors.Dedicated
             base.Refresh();
 
             // Check if parameters group is still showing if not in play mode and hide it.
-            if (!Editor.Instance.StateMachine.IsPlayMode)
+            if (!Editor.Instance.StateMachine.IsPlayMode && _parametersAdded)
             {
                 var group = Layout.Children.Find(x => x is GroupElement g && g.Panel.HeaderText.Equals("Parameters", StringComparison.Ordinal));
                 if (group != null)
                 {
                     RebuildLayout();
+                    _parametersAdded = false;
                 }
             }
         }