diff --git a/core/src/main/java/de/erethon/dungeonsxl/sign/windup/CommandTask.java b/core/src/main/java/de/erethon/dungeonsxl/sign/windup/CommandTask.java
index 703d1145..138c8119 100644
--- a/core/src/main/java/de/erethon/dungeonsxl/sign/windup/CommandTask.java
+++ b/core/src/main/java/de/erethon/dungeonsxl/sign/windup/CommandTask.java
@@ -49,7 +49,7 @@ public class CommandTask extends BukkitRunnable {
 
     @Override
     public void run() {
-        if (isWorldFinished()) {
+        if (sign.isWorldFinished()) {
             sign.deactivate();
             return;
         }
diff --git a/core/src/main/java/de/erethon/dungeonsxl/sign/windup/DelayedPowerTask.java b/core/src/main/java/de/erethon/dungeonsxl/sign/windup/DelayedPowerTask.java
index eaa5b6d2..60f676e2 100644
--- a/core/src/main/java/de/erethon/dungeonsxl/sign/windup/DelayedPowerTask.java
+++ b/core/src/main/java/de/erethon/dungeonsxl/sign/windup/DelayedPowerTask.java
@@ -16,6 +16,7 @@
  */
 package de.erethon.dungeonsxl.sign.windup;
 
+import de.erethon.dungeonsxl.api.DungeonsAPI;
 import org.bukkit.scheduler.BukkitRunnable;
 
 /**
@@ -23,17 +24,19 @@ import org.bukkit.scheduler.BukkitRunnable;
  */
 public class DelayedPowerTask extends BukkitRunnable {
 
+    private DungeonsAPI api;
+
     private RedstoneSign sign;
     private boolean enable;
 
-    public DelayedPowerTask(RedstoneSign sign, boolean enable) {
+    public DelayedPowerTask(DungeonsAPI api, RedstoneSign sign, boolean enable) {
         this.sign = sign;
         this.enable = enable;
     }
 
     @Override
     public void run() {
-        if (isWorldFinished()) {
+        if (api.getGameWorld(sign.getSign().getWorld()) != null) {
             sign.getEnableTask().cancel();
             sign.getDisableTask().cancel();
             return;
diff --git a/core/src/main/java/de/erethon/dungeonsxl/sign/windup/DropSign.java b/core/src/main/java/de/erethon/dungeonsxl/sign/windup/DropSign.java
index 7345fa6a..9855857e 100644
--- a/core/src/main/java/de/erethon/dungeonsxl/sign/windup/DropSign.java
+++ b/core/src/main/java/de/erethon/dungeonsxl/sign/windup/DropSign.java
@@ -93,10 +93,14 @@ public class DropSign extends Windup {
         setRunnable(new BukkitRunnable() {
             @Override
             public void run() {
+                if (isWorldFinished()) {
+                    deactivate();
+                    return;
+                }
                 try {
                     spawnLocation.getWorld().dropItem(spawnLocation, getItem());
                 } catch (NullPointerException exception) {
-                    cancel();
+                    deactivate();
                 }
             }
         });
diff --git a/core/src/main/java/de/erethon/dungeonsxl/sign/windup/MobSpawnTask.java b/core/src/main/java/de/erethon/dungeonsxl/sign/windup/MobSpawnTask.java
index 3239eebb..b44d9003 100644
--- a/core/src/main/java/de/erethon/dungeonsxl/sign/windup/MobSpawnTask.java
+++ b/core/src/main/java/de/erethon/dungeonsxl/sign/windup/MobSpawnTask.java
@@ -35,7 +35,7 @@ public class MobSpawnTask extends BukkitRunnable {
 
     @Override
     public void run() {
-        if (isWorldFinished()) {
+        if (sign.isWorldFinished()) {
             sign.deactivate();
             return;
         }
diff --git a/core/src/main/java/de/erethon/dungeonsxl/sign/windup/RedstoneSign.java b/core/src/main/java/de/erethon/dungeonsxl/sign/windup/RedstoneSign.java
index da1eab8c..0447baba 100644
--- a/core/src/main/java/de/erethon/dungeonsxl/sign/windup/RedstoneSign.java
+++ b/core/src/main/java/de/erethon/dungeonsxl/sign/windup/RedstoneSign.java
@@ -22,7 +22,6 @@ import de.erethon.dungeonsxl.api.DungeonsAPI;
 import de.erethon.dungeonsxl.api.sign.Rocker;
 import de.erethon.dungeonsxl.api.world.InstanceWorld;
 import de.erethon.dungeonsxl.player.DPermission;
-import org.bukkit.block.Block;
 import org.bukkit.block.Sign;
 import org.bukkit.scheduler.BukkitTask;
 
@@ -157,11 +156,11 @@ public class RedstoneSign extends Rocker {
         }
 
         if (delay > 0) {
-            enableTask = new DelayedPowerTask(this, true).runTaskTimer(api, delay, delay + offDelay);
+            enableTask = new DelayedPowerTask(api, this, true).runTaskTimer(api, delay, delay + offDelay);
 
             if (repeat != 1) {
                 repeatsToDo = repeat;
-                disableTask = new DelayedPowerTask(this, false).runTaskTimer(api, delay + offDelay, delay + offDelay);
+                disableTask = new DelayedPowerTask(api, this, false).runTaskTimer(api, delay + offDelay, delay + offDelay);
             }
 
         } else {