What does this mean??

Call stack:

  • ArgumentOutOfRangeException: Index was out of range. Must be non-negative and less than the size of the collection.
  • Parameter name: index
  • System.ThrowHelper.ThrowArgumentOutOfRangeException (System.ExceptionArgument argument, System.ExceptionResource resource) (at :0)
  • System.ThrowHelper.ThrowArgumentOutOfRangeException () (at :0)
  • UnityEngine.UIElements.VisualElement+Hierarchy.get_Item (System.Int32 key) (at <1cdf5c2cc10149169242b9590b7ebb6b>:0)
  • UnityEngine.UIElements.EventDispatchUtilities.PropagateToIMGUIContainer (UnityEngine.UIElements.VisualElement root, UnityEngine.UIElements.EventBase evt) (at <1cdf5c2cc10149169242b9590b7ebb6b>:0)
  • UnityEngine.UIElements.MouseEventDispatchingStrategy.SendEventToIMGUIContainer (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.BaseVisualElementPanel panel) (at <1cdf5c2cc10149169242b9590b7ebb6b>:0)
  • UnityEngine.UIElements.MouseEventDispatchingStrategy.SendEventToTarget (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.BaseVisualElementPanel panel) (at <1cdf5c2cc10149169242b9590b7ebb6b>:0)
  • UnityEngine.UIElements.MouseEventDispatchingStrategy.DispatchEvent (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.IPanel iPanel) (at <1cdf5c2cc10149169242b9590b7ebb6b>:0)
  • UnityEngine.UIElements.EventDispatcher.ApplyDispatchingStrategies (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.IPanel panel, System.Boolean imguiEventIsInitiallyUsed) (at <1cdf5c2cc10149169242b9590b7ebb6b>:0)
  • UnityEngine.UIElements.EventDispatcher.ProcessEvent (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.IPanel panel) (at <1cdf5c2cc10149169242b9590b7ebb6b>:0)
  • UnityEngine.UIElements.EventDispatcher.Dispatch (UnityEngine.UIElements.EventBase evt, UnityEngine.UIElements.IPanel panel, UnityEngine.UIElements.DispatchMode dispatchMode) (at <1cdf5c2cc10149169242b9590b7ebb6b>:0)
  • UnityEngine.UIElements.BaseVisualElementPanel.SendEvent (UnityEngine.UIElements.EventBase e, UnityEngine.UIElements.DispatchMode dispatchMode) (at <1cdf5c2cc10149169242b9590b7ebb6b>:0)
  • UnityEngine.UIElements.UIElementsUtility.DoDispatch (UnityEngine.UIElements.BaseVisualElementPanel panel) (at <1cdf5c2cc10149169242b9590b7ebb6b>:0)
  • UnityEngine.UIElements.UIElementsUtility.UnityEngine.UIElements.IUIElementsUtility.ProcessEvent (System.Int32 instanceID, System.IntPtr nativeEventPtr, System.Boolean& eventHandled) (at <1cdf5c2cc10149169242b9590b7ebb6b>:0)
  • UnityEngine.UIElements.UIEventRegistration.ProcessEvent (System.Int32 instanceID, System.IntPtr nativeEventPtr) (at <1cdf5c2cc10149169242b9590b7ebb6b>:0)
  • UnityEngine.UIElements.UIEventRegistration+<>c.<.cctor>b__1_2 (System.Int32 i, System.IntPtr ptr) (at <1cdf5c2cc10149169242b9590b7ebb6b>:0)
  • UnityEngine.GUIUtility.ProcessEvent (System.Int32 instanceID, System.IntPtr nativeEventPtr, System.Boolean& result) (at :0)
    _
    This is my code

Please Help I’m a beginner in C# So don’t know what it means.

Always start with reading what call stacks says. At the bottom you should see who is calling first and read upward from there. About every line represents another step in a chain of calls that led to the exception visible at the top.

When you do that you will figure out that:

  1. UnityEngine.GUIUtility.ProcessEvent means this call chain started in UI processing code
  2. It’s not your fault at all because you’re not even touching UI code
  3. Call stack mentions none of your code ( PlayerMovement class is nowhere to be found there) - it’s a best proof this wasn’t caused you. It’s probably some minor editor bug. Restart and it (hopefully goes away), if not - well just live with it.