null fixes

src/PixiEditor.Extensions/Palettes/FilteringSettings.cs

@@ -29,7 +29,7 @@ public sealed class FilteringSettings
             return false;
         }
 
-        result = (ShowOnlyFavourites && Favourites.Contains(palette.Name)) || !ShowOnlyFavourites;
+        result = (ShowOnlyFavourites && Favourites != null && Favourites.Contains(palette.Name)) || !ShowOnlyFavourites;
 
         if (!result)
         {

src/PixiEditor/App.xaml.cs

@@ -2,17 +2,13 @@
 using System.Text.RegularExpressions;
 using System.Windows;
 using System.Windows.Media;
-using Microsoft.Extensions.DependencyInjection;
-using PixiEditor.Extensions;
 using PixiEditor.Extensions.Common.Localization;
 using PixiEditor.Models.AppExtensions;
 using PixiEditor.Helpers.UI;
-using PixiEditor.Localization;
 using PixiEditor.Models.Controllers;
 using PixiEditor.Models.DataHolders;
 using PixiEditor.Models.Dialogs;
 using PixiEditor.Models.Enums;
-using PixiEditor.Models.Localization;
 using PixiEditor.Platform;
 using PixiEditor.Views;
 using PixiEditor.Views.Dialogs;

src/PixiEditor/Views/Dialogs/PalettesBrowser.xaml.cs

@@ -154,7 +154,7 @@ internal partial class PalettesBrowser : Window, IPopupWindow
 
     public FilteringSettings Filtering => filteringSettings ??=
         new FilteringSettings(ColorsNumberMode, ColorsNumber, NameFilter, ShowOnlyFavourites,
-            IPreferences.Current.GetLocalPreference<List<string>>(PreferencesConstants.FavouritePalettes));
+            IPreferences.Current.GetLocalPreference<List<string>>(PreferencesConstants.FavouritePalettes, new List<string>()));
 
     private char[] separators = new char[] { ' ', ',' };