upd

Code/Inventory/Definitions/BaseItemDefinition.cs

@@ -6,9 +6,14 @@ public class BaseItemDefinition : GameResource
 	public string Name { get; set; }
 
 	public string Description { get; set; }
-	[ResourceType( "prefab" )] public GameObject Prefab { get; set; }
+
+	[ResourceType( "prefab" )]
+	public GameObject Prefab { get; set; } = GameObject.GetPrefab( "prefabs/item_parcel.prefab" );
+
 	public Texture ImageTexture { get; set; }
 	public string ImageUrl { get; set; }
 
 	public int MaxCount { get; set; } = 1;
+
+	public virtual Inventar.InventorySlot? GetSlot() => null;
 }

Code/Inventory/Definitions/ClothingItemDefinition.cs

@@ -5,4 +5,5 @@ public class ClothingItemDefinition : BaseItemDefinition, IEquipable
 {
 	[Property] public string ClothUrl { get; set; }
 	public Inventar.InventorySlot Slot { get; set; }
+	public override Inventar.InventorySlot? GetSlot() => Slot;
 }

Code/Inventory/Definitions/WeaponItemDefinition.cs

@@ -6,6 +6,8 @@ namespace Sasalka;
 public class WeaponItemDefinition : BaseItemDefinition, IEquipable
 {
 	public Inventar.InventorySlot Slot { get; set; }
+
+	public override Inventar.InventorySlot? GetSlot() => Slot;
 	public CitizenAnimationHelper.HoldTypes HoldType { get; set; } = CitizenAnimationHelper.HoldTypes.None;
 	[InlineEditor, Space] public WeaponDefinition WeaponDefinition { get; set; }
 }