Please Help

Unity Engine
1

I am new to unity, I first started making games yesterday. so sorry to be such a newbie. But I keep getting this error and I don’t know why. I don’t know if this should be in the UnityGUI section but I see GUI in the error so I thought I should post it here.

NullReferenceException: Object reference not set to an instance of an object
UnityEditor.TreeViewDragging.DragElement (UnityEditor.TreeViewItem targetItem, Rect targetItemRect, Boolean firstItem) (at C:/BuildAgent/work/d63dfc6385190b60/Editor/Mono/GUI/TreeView/TreeViewDragging.cs:201)
UnityEditor.TreeView.HandleUnusedMouseEventsForNode (Rect rect, UnityEditor.TreeViewItem item, Boolean firstItem) (at C:/BuildAgent/work/d63dfc6385190b60/Editor/Mono/GUI/TreeView/TreeView.cs:304)
UnityEditor.TreeView.OnGUI (Rect rect, Int32 keyboardControlID) (at C:/BuildAgent/work/d63dfc6385190b60/Editor/Mono/GUI/TreeView/TreeView.cs:408)
UnityEditor.SceneHierarchyWindow.DoTreeView () (at C:/BuildAgent/work/d63dfc6385190b60/Editor/Mono/SceneHierarchyWindow.cs:273)
UnityEditor.SceneHierarchyWindow.OnGUI () (at C:/BuildAgent/work/d63dfc6385190b60/Editor/Mono/SceneHierarchyWindow.cs:159)
System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[ ] parameters, System.Globalization.CultureInfo culture) (at /Users/builduser/buildslave/mono-runtime-and-classlibs/build/mcs/class/corlib/System.Reflection/MonoMethod.cs:222)

thank you for helping.

2

I just updated to Unity 4.5.3f3 (from about 4.5.1) and now I am getting this error while dragging objects around both in the hierarchy and dragging them to my folder of prefabs from the hierarchy. Specifically, it starts to happen while I have an object grabbed and am hovering the mouse between two items in the hierarchy. It doesn’t happen immediately, but starts to print errors after a second or two.

I’ve never seen this error before in the previous 6 months that I’ve been using Unity, so I’m suspicious of it being a bug in the newer version. I’m not doing anything differently than I used to.

3

I’m also getting this issue now in 4.5.3f3

It doesn’t seem to happen consistently, but it is pretty frequent. I do have a couple objects marked as hidden with HideFlags, so I wonder if it has to do with them somehow.