diff --git a/spine-unity/Assets/Spine/Editor/spine-unity/Editor/Components/SkeletonGraphicInspector.cs b/spine-unity/Assets/Spine/Editor/spine-unity/Editor/Components/SkeletonGraphicInspector.cs
index c4c6982d2..584925296 100644
--- a/spine-unity/Assets/Spine/Editor/spine-unity/Editor/Components/SkeletonGraphicInspector.cs
+++ b/spine-unity/Assets/Spine/Editor/spine-unity/Editor/Components/SkeletonGraphicInspector.cs
@@ -361,7 +361,8 @@ namespace Spine.Unity.Editor {
 				if (skeleton != null) {
 					for (int i = 0, n = separatorSlotNames.arraySize; i < n; i++) {
 						string slotName = separatorSlotNames.GetArrayElementAtIndex(i).stringValue;
-						int index = skeleton.Data.FindSlot(slotName).Index;
+						SlotData slot = skeleton.Data.FindSlot(slotName);
+						int index = slot != null ? slot.Index : -1;
 						if (index == 0 || index == lastSlot) {
 							hasTerminalSlot = true;
 							break;
diff --git a/spine-unity/Assets/Spine/Editor/spine-unity/Editor/Components/SkeletonRendererInspector.cs b/spine-unity/Assets/Spine/Editor/spine-unity/Editor/Components/SkeletonRendererInspector.cs
index c0b835ff4..abff041fd 100644
--- a/spine-unity/Assets/Spine/Editor/spine-unity/Editor/Components/SkeletonRendererInspector.cs
+++ b/spine-unity/Assets/Spine/Editor/spine-unity/Editor/Components/SkeletonRendererInspector.cs
@@ -483,7 +483,8 @@ namespace Spine.Unity.Editor {
 				if (skeleton != null) {
 					for (int i = 0, n = separatorSlotNames.arraySize; i < n; i++) {
 						string slotName = separatorSlotNames.GetArrayElementAtIndex(i).stringValue;
-						int index = skeleton.Data.FindSlot(slotName).Index;
+						SlotData slot = skeleton.Data.FindSlot(slotName);
+						int index = slot != null ? slot.Index : -1;
 						if (index == 0 || index == lastSlot) {
 							hasTerminalSlot = true;
 							break;
diff --git a/spine-unity/Assets/Spine/Runtime/spine-unity/Components/SkeletonUtility/SkeletonUtility.cs b/spine-unity/Assets/Spine/Runtime/spine-unity/Components/SkeletonUtility/SkeletonUtility.cs
index 545c7e7f8..eb5add172 100644
--- a/spine-unity/Assets/Spine/Runtime/spine-unity/Components/SkeletonUtility/SkeletonUtility.cs
+++ b/spine-unity/Assets/Spine/Runtime/spine-unity/Components/SkeletonUtility/SkeletonUtility.cs
@@ -53,7 +53,8 @@ namespace Spine.Unity {
 				return null;
 			}
 
-			var attachment = skin.GetAttachment(skeleton.Data.FindSlot(slotName).Index, attachmentName);
+			Slot slot = skeleton.FindSlot(slotName);
+			var attachment = slot != null ? skin.GetAttachment(slot.Data.Index, attachmentName) : null;
 			if (attachment == null) {
 				Debug.LogFormat("Attachment in slot '{0}' named '{1}' not found in skin '{2}'.", slotName, attachmentName, skin.Name);
 				return null;
@@ -61,7 +62,6 @@ namespace Spine.Unity {
 
 			var box = attachment as BoundingBoxAttachment;
 			if (box != null) {
-				var slot = skeleton.FindSlot(slotName);
 				return AddBoundingBoxGameObject(box.Name, box, slot, parent, isTrigger);
 			} else {
 				Debug.LogFormat("Attachment '{0}' was not a Bounding Box.", attachmentName);
diff --git a/spine-unity/Assets/Spine/Runtime/spine-unity/SpineAttributes.cs b/spine-unity/Assets/Spine/Runtime/spine-unity/SpineAttributes.cs
index 2439a1887..a7a4e1264 100644
--- a/spine-unity/Assets/Spine/Runtime/spine-unity/SpineAttributes.cs
+++ b/spine-unity/Assets/Spine/Runtime/spine-unity/SpineAttributes.cs
@@ -252,10 +252,11 @@ namespace Spine.Unity {
 
 		public static Spine.Attachment GetAttachment (string attachmentPath, Spine.SkeletonData skeletonData) {
 			var hierarchy = SpineAttachment.GetHierarchy(attachmentPath);
-			return string.IsNullOrEmpty(hierarchy.name) ?
-				null :
-				skeletonData.FindSkin(hierarchy.skin).GetAttachment(
-					skeletonData.FindSlot(hierarchy.slot).Index, hierarchy.name);
+			if (string.IsNullOrEmpty(hierarchy.name)) return null;
+
+			SlotData slot = skeletonData.FindSlot(hierarchy.slot);
+			if (slot == null) return null;
+			return skeletonData.FindSkin(hierarchy.skin).GetAttachment(slot.Index, hierarchy.name);
 		}
 
 		public static Spine.Attachment GetAttachment (string attachmentPath, SkeletonDataAsset skeletonDataAsset) {