Error when change texture to sprite(2D & UI) uity 5.1f win xp 32

In the past i used unity 5.0 and all been ok but 2 weeks ago i update’d to 5.1.1f and now i have the problem. When i try to change texture to sprite i have this error :

NullReferenceException: Object reference not set to an instance of an object
UnityEditor.SpriteEditorWindow.ApplyCacheSettingsToInspector (UnityEditor.SerializedObject so) (at C:/buildslave/unity/build/Editor/Mono/SpriteEditor/SpriteEditorWindow.cs:143)
UnityEditor.SpriteEditorWindow.TextureImporterApply (UnityEditor.SerializedObject so) (at C:/buildslave/unity/build/Editor/Mono/SpriteEditor/SpriteEditorWindow.cs:138)
UnityEditor.TextureImporterInspector.Apply () (at C:/buildslave/unity/build/Editor/Mono/ImportSettings/TextureImporterInspector.cs:2201)
UnityEditor.AssetImporterInspector.ApplyAndImport () (at C:/buildslave/unity/build/Editor/Mono/ImportSettings/AssetImporterInspector.cs:148)
UnityEditor.AssetImporterInspector.ApplyButton (System.String buttonText) (at C:/buildslave/unity/build/Editor/Mono/ImportSettings/AssetImporterInspector.cs:199)
UnityEditor.AssetImporterInspector.ApplyButton () (at C:/buildslave/unity/build/Editor/Mono/ImportSettings/AssetImporterInspector.cs:192)
UnityEditor.AssetImporterInspector.ApplyRevertGUIButtons () (at C:/buildslave/unity/build/Editor/Mono/ImportSettings/AssetImporterInspector.cs:210)
UnityEditor.AssetImporterInspector.ApplyRevertGUI () (at C:/buildslave/unity/build/Editor/Mono/ImportSettings/AssetImporterInspector.cs:226)
UnityEditor.TextureImporterInspector.OnInspectorGUI () (at C:/buildslave/unity/build/Editor/Mono/ImportSettings/TextureImporterInspector.cs:1329)
UnityEditor.InspectorWindow.DrawEditor (UnityEditor.Editor editor, Int32 editorIndex, Boolean forceDirty, System.Boolean& showImportedObjectBarNext, UnityEngine.Rect& importedObjectBarRect, Boolean eyeDropperDirty) (at C:/buildslave/unity/build/Editor/Mono/Inspector/InspectorWindow.cs:1162)
UnityEditor.DockArea:OnGUI()

C’on there isn’t any guy from unity tech?

Same here… closing the buggy Sprite Editor worked for me! :wink:

i dont know what that mean?

i can not open a sprite editor

A-ha!

Yes, closing the Sprite Editor tab works!