diff --git a/event-loop/src/main/java/mc/core/events/api/interfaces/PlayerProvidingEvent.java b/event-loop/src/main/java/mc/core/events/api/interfaces/PlayerProvidingEvent.java
index b434061..d05af39 100644
--- a/event-loop/src/main/java/mc/core/events/api/interfaces/PlayerProvidingEvent.java
+++ b/event-loop/src/main/java/mc/core/events/api/interfaces/PlayerProvidingEvent.java
@@ -2,7 +2,6 @@ package mc.core.events.api.interfaces;
 
 import mc.core.Location;
 import mc.core.player.Player;
-import sun.reflect.generics.reflectiveObjects.NotImplementedException;
 
 import java.util.Collection;
 import java.util.Collections;
@@ -17,6 +16,6 @@ public interface PlayerProvidingEvent extends LocationProvidingEvent {
         if (players.size() == 1)
             return Collections.singletonList(players.get(0).getLocation());
         else
-            throw new NotImplementedException();
+            throw new RuntimeException("This method is not implemented.");
     }
 }
diff --git a/event-loop/src/main/java/mc/core/events/api/samples/BlockBreakEvent.java b/event-loop/src/main/java/mc/core/events/api/samples/BlockBreakEvent.java
index 5753491..a515022 100644
--- a/event-loop/src/main/java/mc/core/events/api/samples/BlockBreakEvent.java
+++ b/event-loop/src/main/java/mc/core/events/api/samples/BlockBreakEvent.java
@@ -3,11 +3,11 @@ package mc.core.events.api.samples;
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
 import mc.core.Location;
-import mc.core.block.Block;
 import mc.core.events.EventBase;
 import mc.core.events.api.interfaces.LocationProvidingEvent;
 import mc.core.events.api.interfaces.PlayerProvidingEvent;
 import mc.core.player.Player;
+import mc.core.world.block.Block;
 
 import java.util.Collection;
 import java.util.Collections;
@@ -19,7 +19,6 @@ public class BlockBreakEvent extends EventBase implements PlayerProvidingEvent,
     private final Player player;
     private final Block block;
 
-
     @Override
     public List<Player> getAssociatedPlayers() {
         return Collections.singletonList(player);
diff --git a/event-loop/src/main/java/mc/core/events/runner/ResourceAwareExecutorService.java b/event-loop/src/main/java/mc/core/events/runner/ResourceAwareExecutorService.java
index 77637c7..0ec99ca 100644
--- a/event-loop/src/main/java/mc/core/events/runner/ResourceAwareExecutorService.java
+++ b/event-loop/src/main/java/mc/core/events/runner/ResourceAwareExecutorService.java
@@ -1,7 +1,5 @@
 package mc.core.events.runner;
 
-import sun.plugin.dom.exception.InvalidStateException;
-
 import java.util.HashSet;
 import java.util.Iterator;
 import java.util.Set;
@@ -35,7 +33,7 @@ public class ResourceAwareExecutorService {
 
     public void start() {
         if (executorThreads.size() > 0)
-            throw new InvalidStateException("This executor service was already started.");
+            throw new RuntimeException("This executor service was already started.");
 
         for (int i = 0; i < threadCount; i++) {
             Thread thread = new ExecutorWorkerThread("Event Loop #" + i, this);
@@ -46,7 +44,7 @@ public class ResourceAwareExecutorService {
 
     public void stop() {
         if (executorThreads.size() == 0)
-            throw new InvalidStateException("This executor service was not initialized yet.");
+            throw new RuntimeException("This executor service was not initialized yet.");
 
         Iterator<Thread> iterator = executorThreads.iterator();
         while (iterator.hasNext()) {