diff --git a/src/main/java/de/erethon/dungeonsxl/sign/BlockSign.java b/src/main/java/de/erethon/dungeonsxl/sign/BlockSign.java
index f665f16a..7279fb5e 100644
--- a/src/main/java/de/erethon/dungeonsxl/sign/BlockSign.java
+++ b/src/main/java/de/erethon/dungeonsxl/sign/BlockSign.java
@@ -50,32 +50,41 @@ public class BlockSign extends DSign {
     public void onInit() {
         if (lines[1].isEmpty()) {
             offBlock = VanillaItem.AIR;
-        } else if (lines[2].isEmpty()) {
+
+        } else {
+            String[] line1 = lines[1].split(",");
+            offBlock = plugin.getCaliburn().getExItem(line1[0]);
+            if (offBlock == null) {
+                markAsErroneous("Could not recognize offBlock, input: " + lines[1]);
+                return;
+            }
+            if (line1.length > 1) {
+                offBlockData = (byte) NumberUtil.parseInt(line1[1]);
+            }
+        }
+
+        if (lines[2].isEmpty()) {
             onBlock = VanillaItem.AIR;
-        }
 
-        String[] line1 = lines[1].split(",");
-        offBlock = plugin.getCaliburn().getExItem(line1[0]);
-        if (offBlock == null) {
-            markAsErroneous("Could not recognize offBlock, input: " + lines[1]);
-            return;
-        }
-        if (line1.length > 1) {
-            offBlockData = (byte) NumberUtil.parseInt(line1[1]);
-        }
-
-        String[] line2 = lines[2].split(",");
-        onBlock = plugin.getCaliburn().getExItem(line2[0]);
-        if (onBlock == null) {
-            markAsErroneous("Could not recognize onBlock, input: " + lines[2]);
-            return;
-        }
-        if (line2.length > 1) {
-            onBlockData = (byte) NumberUtil.parseInt(line2[1]);
+        } else {
+            String[] line2 = lines[2].split(",");
+            onBlock = plugin.getCaliburn().getExItem(line2[0]);
+            if (onBlock == null) {
+                markAsErroneous("Could not recognize onBlock, input: " + lines[2]);
+                return;
+            }
+            if (line2.length > 1) {
+                onBlockData = (byte) NumberUtil.parseInt(line2[1]);
+            }
         }
 
         getSign().getBlock().setType(offBlock.getMaterial());
-        getSign().getBlock().setData(offBlockData);
+        try {
+            getSign().getBlock().setData(offBlockData);
+        } catch (IllegalArgumentException exception) {
+            markAsErroneous("offBlock data value " + offBlockData + " cannot be applied to given type " + offBlock.getId());
+            return;
+        }
         initialized = true;
     }
 
@@ -83,7 +92,12 @@ public class BlockSign extends DSign {
     public void onTrigger() {
         if (initialized && !active) {
             getSign().getBlock().setType(onBlock.getMaterial());
-            getSign().getBlock().setData(onBlockData);
+            try {
+                getSign().getBlock().setData(onBlockData);
+            } catch (IllegalArgumentException exception) {
+                markAsErroneous("onBlock data value " + onBlockData + " cannot be applied to given type " + onBlock.getId());
+                return;
+            }
             active = true;
         }
     }