SWItem can not be null

SpigotCore_Main/src/de/steamwar/inventory/SWItem.java

@@ -89,11 +89,17 @@ public class SWItem {
 
     @SuppressWarnings("deprecation")
     public SWItem(Material material, byte meta, String name, List<String> lore, boolean enchanted, InvCallback c) {
+
+        if(material != null) {
             try {
-            itemStack = new ItemStack(material, 1, (short)0, meta);
+                itemStack = new ItemStack(material, 1, (short) 0, meta);
             } catch (IllegalArgumentException e) {
                 itemStack = new ItemStack(material, 1);
             }
+        }else {
+            itemStack = new ItemStack(Material.BARRIER, 1);
+        }
+
         itemMeta = itemStack.getItemMeta();
 
         if (itemMeta != null) {

SpigotCore_Main/src/de/steamwar/inventory/SchematicSelector.java

@@ -235,10 +235,6 @@ public class SchematicSelector {
     private SWListInv.SWListEntry<SchematicNode> renderItem(SchematicNode node) {
         Material m = SWItem.getMaterial(node.getItem());
 
-        if(m == null) {
-            m = Material.BARRIER;
-        }
-
         String name = Core.MESSAGE.parse(filter.name == null?"SCHEM_SELECTOR_ITEM_NAME":"SCHEM_SELECTOR_ITEM_NAME_FILTER", player, node.getName());
 
         if(filter.getName() != null) {