Renamed GridCoordinates.Nullspace to GridCoordinates.InvalidGrid, because it has nothing to do with Nullspace anymore.

Content.Server/GameObjects/Components/GUI/ServerHandsComponent.cs

@@ -482,7 +482,7 @@ namespace Content.Server.GameObjects
                         if (used != null)
                         {
                             interactionSystem.Interaction(Owner, used, slot.ContainedEntity,
-                                GridCoordinates.Nullspace);
+                                GridCoordinates.InvalidGrid);
                         }
                         else
                         {

Content.Server/GameObjects/Components/Stack/StackComponent.cs

@@ -18,7 +18,6 @@ namespace Content.Server.GameObjects.Components.Stack
     [RegisterComponent]
     public class StackComponent : Component, IAttackBy, IExamine
     {
-
 #pragma warning disable 649
         [Dependency] private readonly ISharedNotifyManager _sharedNotifyManager;
 #pragma warning restore 649
@@ -122,7 +121,7 @@ namespace Content.Server.GameObjects.Components.Stack
                 stack.Add(toTransfer);
 
                 var popupPos = eventArgs.ClickLocation;
-                if (popupPos == GridCoordinates.Nullspace)
+                if (popupPos == GridCoordinates.InvalidGrid)
                 {
                     popupPos = eventArgs.User.Transform.GridPosition;
                 }