diff --git a/Server/src/net/simon987/server/GameServer.java b/Server/src/net/simon987/server/GameServer.java
index 8a6b8de..02c16ea 100644
--- a/Server/src/net/simon987/server/GameServer.java
+++ b/Server/src/net/simon987/server/GameServer.java
@@ -104,10 +104,11 @@ public class GameServer implements Runnable {
 
         //Process user code
         for(User user : gameUniverse.getUsers()){
-            user.getCpu().reset();
-            user.getCpu().execute();
 
-//            System.out.println(user.getCpu());
+            if(user.getCpu() != null){
+                user.getCpu().reset();
+                user.getCpu().execute();
+            }
         }
 
         //Process each worlds
diff --git a/Server/src/net/simon987/server/game/GameUniverse.java b/Server/src/net/simon987/server/game/GameUniverse.java
index dc14918..941b1ae 100644
--- a/Server/src/net/simon987/server/game/GameUniverse.java
+++ b/Server/src/net/simon987/server/game/GameUniverse.java
@@ -98,23 +98,24 @@ public class GameUniverse implements JSONSerialisable{
             try {
                 if(makeControlledUnit) {
                     user = new User();
+                    user.setCpu(new CPU(GameServer.INSTANCE.getConfig(), user));
+                    user.setUserCode(GameServer.INSTANCE.getConfig().getString("new_user_code"));
+
+                    //Compile user code
+                    AssemblyResult ar = new Assembler(user.getCpu().getInstructionSet(), user.getCpu().getRegisterSet(),
+                            GameServer.INSTANCE.getConfig()).parse(user.getUserCode());
+
+                    user.getCpu().getMemory().clear();
+
+                    //Write assembled code to mem
+                    user.getCpu().getMemory().write((short) ar.origin, ar.bytes, ar.bytes.length);
+                    user.getCpu().setCodeSegmentOffset(ar.origin);
+
                 } else {
                     user = new User(null);
                 }
 
                 user.setUsername(username);
-                user.setCpu(new CPU(GameServer.INSTANCE.getConfig(), user));
-                user.setUserCode(GameServer.INSTANCE.getConfig().getString("new_user_code"));
-
-                //Compile user code
-                AssemblyResult ar = new Assembler(user.getCpu().getInstructionSet(), user.getCpu().getRegisterSet(),
-                        GameServer.INSTANCE.getConfig()).parse(user.getUserCode());
-
-                user.getCpu().getMemory().clear();
-
-                //Write assembled code to mem
-                user.getCpu().getMemory().write((short) ar.origin, ar.bytes, ar.bytes.length);
-                user.getCpu().setCodeSegmentOffset(ar.origin);
 
                 users.add(user);
 
diff --git a/Server/src/net/simon987/server/webserver/SocketServer.java b/Server/src/net/simon987/server/webserver/SocketServer.java
index e897332..2c510e0 100644
--- a/Server/src/net/simon987/server/webserver/SocketServer.java
+++ b/Server/src/net/simon987/server/webserver/SocketServer.java
@@ -39,14 +39,13 @@ public class SocketServer extends WebSocketServer {
     @Override
     public void onOpen(WebSocket conn, ClientHandshake handshake) {
         LogManager.LOGGER.info("(WS) New Websocket connection " + conn.getRemoteSocketAddress());
-
         userManager.add(new OnlineUser(conn));
     }
 
     @Override
     public void onClose(WebSocket conn, int code, String reason, boolean remote) {
         LogManager.LOGGER.info("(WS) Closed " + conn.getRemoteSocketAddress() + " with exit code " + code + " additional info: " + reason);
-        userManager.add(new OnlineUser(conn));
+        userManager.remove(userManager.getUser(conn));
     }
 
     @Override
@@ -110,6 +109,8 @@ public class SocketServer extends WebSocketServer {
     @Override
     public void onError(WebSocket conn, Exception ex) {
         System.err.println("an error occured on connection " + conn.getRemoteSocketAddress() + ':' + ex);
+        userManager.remove(userManager.getUser(conn));
+
         ex.printStackTrace();
     }