diff --git a/src/main/java/de/bixilon/minosoft/gui/main/MainWindow.java b/src/main/java/de/bixilon/minosoft/gui/main/MainWindow.java
index 7c52b19b2..edb403d83 100644
--- a/src/main/java/de/bixilon/minosoft/gui/main/MainWindow.java
+++ b/src/main/java/de/bixilon/minosoft/gui/main/MainWindow.java
@@ -86,6 +86,9 @@ public class MainWindow implements Initializable {
     }
 
     public static void selectAccount() {
+        if (menuAccount2 == null) {
+            return;
+        }
         if (Minosoft.getSelectedAccount() != null) {
             menuAccount2.setText(LocaleManager.translate(Strings.MAIN_WINDOW_MENU_SERVERS_ACCOUNTS_SELECTED, Minosoft.getSelectedAccount().getPlayerName()));
         } else {
diff --git a/src/main/java/de/bixilon/minosoft/gui/main/Server.java b/src/main/java/de/bixilon/minosoft/gui/main/Server.java
index 0e2ef4a29..5a1693e23 100644
--- a/src/main/java/de/bixilon/minosoft/gui/main/Server.java
+++ b/src/main/java/de/bixilon/minosoft/gui/main/Server.java
@@ -93,7 +93,7 @@ public class Server {
 
     @Override
     public String toString() {
-        return getName() + " (" + getAddress() + ")";
+        return String.format("%s (%s)", getName(), getAddress());
     }
 
     public String getName() {
diff --git a/src/main/java/de/bixilon/minosoft/protocol/network/netty/PacketDecoder.java b/src/main/java/de/bixilon/minosoft/protocol/network/netty/PacketDecoder.java
index 94ac1684e..1369535d4 100644
--- a/src/main/java/de/bixilon/minosoft/protocol/network/netty/PacketDecoder.java
+++ b/src/main/java/de/bixilon/minosoft/protocol/network/netty/PacketDecoder.java
@@ -100,7 +100,7 @@ public class PacketDecoder extends ByteToMessageDecoder {
             if (packet == null) {
                 Log.fatal(String.format("Packet mapping does not contain a packet with id 0x%x. The server sends bullshit or your versions.json broken!", inPacketBuffer.getCommand()));
                 nettyNetwork.disconnect();
-                throw new RuntimeException("Invalid packet 0x%x" + inPacketBuffer.getCommand());
+                throw new RuntimeException(String.format("Invalid packet 0x%x", inPacketBuffer.getCommand()));
             }
             Class<? extends ClientboundPacket> clazz = packet.getClazz();
 
diff --git a/src/main/java/de/bixilon/minosoft/protocol/network/socket/SocketNetwork.java b/src/main/java/de/bixilon/minosoft/protocol/network/socket/SocketNetwork.java
index 42db88532..e274abd29 100644
--- a/src/main/java/de/bixilon/minosoft/protocol/network/socket/SocketNetwork.java
+++ b/src/main/java/de/bixilon/minosoft/protocol/network/socket/SocketNetwork.java
@@ -195,7 +195,7 @@ public class SocketNetwork implements Network {
                         if (packet == null) {
                             Log.fatal(String.format("Packet mapping does not contain a packet with id 0x%x. The server sends bullshit or your versions.json broken!", inPacketBuffer.getCommand()));
                             disconnect();
-                            lastException = new RuntimeException("Invalid packet 0x" + inPacketBuffer.getCommand());
+                            lastException = new RuntimeException(String.format("Invalid packet 0x%x", inPacketBuffer.getCommand()));
                             throw lastException;
                         }
                         Class<? extends ClientboundPacket> clazz = packet.getClazz();
diff --git a/src/main/java/de/bixilon/minosoft/util/nbt/tag/StringTag.java b/src/main/java/de/bixilon/minosoft/util/nbt/tag/StringTag.java
index d6bc133ef..7b57284a2 100644
--- a/src/main/java/de/bixilon/minosoft/util/nbt/tag/StringTag.java
+++ b/src/main/java/de/bixilon/minosoft/util/nbt/tag/StringTag.java
@@ -44,6 +44,6 @@ public class StringTag extends NBTTag {
 
     @Override
     public String toString() {
-        return "\"" + value + "\"";
+        return String.format("\"%s\"", value);
     }
 }