diff --git a/Qwirkle/QwirkleClassLibrary/Games/Game.cs b/Qwirkle/QwirkleClassLibrary/Games/Game.cs
index 07d0050..9c9c078 100644
--- a/Qwirkle/QwirkleClassLibrary/Games/Game.cs
+++ b/Qwirkle/QwirkleClassLibrary/Games/Game.cs
@@ -1,13 +1,5 @@
-using System;
-using System.Collections.Generic;
-using System.Collections.ObjectModel;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-using System.Xml.Linq;
+using System.Collections.ObjectModel;
 using System.Security.Cryptography;
-using System.Collections;
-using System.Collections.Immutable;
 using System.Runtime.Serialization;
 using QwirkleClassLibrary.Tiles;
 using QwirkleClassLibrary.Boards;
@@ -270,7 +262,7 @@ namespace QwirkleClassLibrary.Games
                 {
                     if (bag != null && p.Tiles.Count < 6)
                     {
-                        int val = RandomNumberGenerator.GetInt32(0, bag.TilesBag.Count);
+                        int val = RandomNumberGenerator.GetInt32(0, bag.TilesBag!.Count);
 
                         p.AddTileToPlayer(bag.TilesBag[val]);
                         bag.RemoveTileInBag(bag.TilesBag[val]);
@@ -362,7 +354,7 @@ namespace QwirkleClassLibrary.Games
         {
             while (player.Tiles.Count < 6)
             {
-                if (bag!.TilesBag.Count == 0)
+                if (bag!.TilesBag!.Count == 0)
                 {
                     return false;
                 }
@@ -396,7 +388,7 @@ namespace QwirkleClassLibrary.Games
                 return false;
             }
 
-            if (bag!.TilesBag.Count < tilesToSwap.Count)
+            if (bag!.TilesBag!.Count < tilesToSwap.Count)
             {
                 OnSwapTiles(new SwapTilesNotifiedEventArgs("Not enough tiles in the bag to swap !"));
                 return false;
@@ -733,7 +725,7 @@ namespace QwirkleClassLibrary.Games
         {
             List<int> playerTilesBagPos = [];
 
-            if (bag!.TilesBag.Count == 0)
+            if (bag!.TilesBag!.Count == 0)
             {
                 for (int i = 0; i < players.Count; i++)
                 {
@@ -785,7 +777,7 @@ namespace QwirkleClassLibrary.Games
         {
             List<int> playerTilesBagPos = CheckTilesBag();
 
-            if (playerTilesBagPos.Count != 0 && !CheckPlacementPossibilities(playerTilesBagPos) || bag!.TilesBag.Count == 0 && players[GetPlayingPlayerPosition()].Tiles.Count==0)
+            if (playerTilesBagPos.Count != 0 && !CheckPlacementPossibilities(playerTilesBagPos) || bag!.TilesBag!.Count == 0 && players[GetPlayingPlayerPosition()].Tiles.Count==0)
             {
                 OnEndOfGame(new EndOfGameNotifiedEventArgs(player));
                 GameRunning = false;
diff --git a/Qwirkle/TestBase/TestPlayer.cs b/Qwirkle/TestBase/TestPlayer.cs
index fbf2147..1727423 100644
--- a/Qwirkle/TestBase/TestPlayer.cs
+++ b/Qwirkle/TestBase/TestPlayer.cs
@@ -11,10 +11,10 @@ public class TestPlayers
         {
             if (!isValid)
             {
-                Assert.Throws<ArgumentNullException>(() => new Player(playertag));
+                Assert.Throws<ArgumentNullException>(() => new Player(playertag!));
                 return;
             }
-            Player player = new Player(playertag);
+            Player player = new Player(playertag!);
             Assert.Equal(playertag, player.NameTag);
         }
 
diff --git a/Qwirkle/TestBase/TestTileBag.cs b/Qwirkle/TestBase/TestTileBag.cs
index cbfc07b..e202809 100644
--- a/Qwirkle/TestBase/TestTileBag.cs
+++ b/Qwirkle/TestBase/TestTileBag.cs
@@ -16,7 +16,7 @@ public class TestTileBag
             return;
         }
         TileBag bag = new TileBag(nbset);
-        Assert.Equal(bag.TilesBag.Count, nbset * 36);
+        Assert.Equal(bag.TilesBag!.Count, nbset * 36);
     }
 
 
@@ -30,11 +30,11 @@ public class TestTileBag
 
         if (except)
         {
-            Assert.True(bag.RemoveTileInBag(bag.TilesBag[1]));
+            Assert.True(bag.RemoveTileInBag(bag.TilesBag![1]));
             return;
         }
 
-        Tile tile = bag.TilesBag[0];
+        Tile tile = bag.TilesBag![0];
 
         bag.RemoveTileInBag(tile);
         Assert.False(bag.RemoveTileInBag(tile));