I've been trying to host a Minecraft server for some time now. I'm practically a complete beginner with Linux thus far, so you may have to explain things to me a bit. I was able to host servers on Windows in the past with relative ease. I'm hosting the server locally through a wireless router.

Through Google, I've done things involving uninstalling OpenJDK and installing Oracle's Java, doing something involving iptables, stopping the ufw service, updating LWJGL, and downloading Firewall software. Nothing has worked yet. I have 25565 forwarded. Neither me nor a friend are able to join via external IP, though I can connect through localhost. It says I'm connecting for some time, then gives me an error:

  • Minecraft Version: 1.4.2
  • Operating System: Linux (amd64) version 3.5.0-17-generic
  • Java Version: 1.7.0_09, Oracle Corporation
  • Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
  • Memory: 396627816 bytes (378 MB) / 514523136 bytes (490 MB) up to 514523136 bytes (490 MB)
  • JVM Flags: 2 total; -Xms512m -Xmx512m
  • AABB Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
  • ModLoader: Mods loaded: 3 ModLoader 1.4.2 mod_MineLittlePony Inventory Tweaks 1.44 (1.4.2)

  • LWJGL: 2.8.4

  • OpenGL: GeForce GTX 560 Ti/PCIe/SSE2 GL version 4.2.0 NVIDIA 304.43, NVIDIA Corporation
  • Is Modded: Very likely
  • Type: Client
  • Texture Pack: Default
  • Profiler Position: N/A (disabled)
  • Vec3 Pool Size: ~ERROR~ NullPointerException: null java.lang.NullPointerException at aww.a(SourceFile:57) at ayt.b(EntityRenderer.java:1149) at EntityRendererProxy.b(EntityRendererProxy.java:20) at net.minecraft.client.Minecraft.J(SourceFile:604) at net.minecraft.client.Minecraft.run(SourceFile:534) at java.lang.Thread.run(Unknown Source)

My friend doesn't get this error however, and instead gets a timeout message, so that's likely something on my end.

If there's any more information you need, I'll gladly supply it if I can.

  • Can I ask why you are doing this wireless? Updating LWJGL is for playing, not hosting a server. Is this log from your server? Since it looks like a client log. And most routers dont let you connect to the external ip, when that is your external ip(in other words, ther server is in the same network). At the ned you say that your friend doesnt get this error, but he was unable to connect to the server?
    – Dr_Bunsen
    Nov 4, 2012 at 21:17
  • My desktop is quite a distance from the router. I did still need to update it to play, just thought it was worth mentioning. I don't recall having issues connecting to my own external IP in the past. This is correct. EDIT: Just had another friend try and, after letting it sit, he got 'Connection timed out'.
    – Alzarath
    Nov 4, 2012 at 21:28
  • Well, I say you have the port 25565 opened 2 times. I don't know if that is going to mess with things. you should try deleting the entry which isnt used, or use another port.
    – Dr_Bunsen
    Nov 5, 2012 at 16:35

2 Answers 2


For starters, there is a big chance those are two different issues

Your friend not connecting might be an incorrect port forward. Google around for a site that will do a port check on your IP (there are tons).

Your error is game client/java related. Verify that you have the correct java version installed (check the one your friend has, if it works for him) and install it like so: How can I install Sun/Oracle's proprietary Java JDK 6/7/8 or JRE?

If that doesn't work try removing the mods? I haven't personally played minecraft (downvotes incoming i guess?) but that's one of the first things i'd try.


I think you just used the external IP. but you must log in with How ever if you are on the same network as your server you can try to log inn with the internal IP from the server. for example: but i thing it doesn’t solve the crash error. But it can MABY be the RAM that is overloaded on your pc. (i am not an expert, but i have hosted some minecraft servers myself)

  • Please take the time to write complete sentences and to express what you really want to say - currently your post makes very little sense.
    – guntbert
    Dec 17, 2014 at 19:28
  • Ok, tanks for the tip. Dec 19, 2014 at 20:08

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