Fixed undo crash and renamed pixel art toolset

src/PixiEditor/Data/Localization/Languages/en.json

@@ -757,7 +757,7 @@
   "MODULO": "Modulo",
   "STEP": "Step",
   "SMOOTH_STEP": "Smoothstep",
-  "PIXEL_PERFECT_TOOLSET": "Pixel Perfect",
+  "PIXEL_PERFECT_TOOLSET": "Pixel Art",
   "VECTOR_TOOLSET": "Vector",
   "VECTOR_LAYER": "Vector Layer",
   "STROKE_COLOR_LABEL": "Stroke",

src/PixiEditor/Models/Rendering/AffectedAreasGatherer.cs

@@ -337,6 +337,7 @@ internal class AffectedAreasGatherer
         for (int i = ignoreSelf ? 1 : 0; i < path.Count; i++)
         {
             var member = path[i];
+            if(member == null) continue;
             if (!ImagePreviewAreas.ContainsKey(member.Id))
             {
                 ImagePreviewAreas[member.Id] = new AffectedArea(area);