Just tried again with ye olde Oracle Java 6. Symptoms are generally the same but log_init.txt is different:


  INFO [Properties.<init>]                           VERSION: 1.3.6
  INFO [Properties.<init>]                           Classpath: ./data.jar
  INFO [Properties.<init>]                           Java VM: 20.45-b01
  INFO [Properties.<init>]                           Java Runtime: 1.6.0_45-b06
  INFO [Properties.<init>]                           OS: Linux 3.11.0-12-generic amd64
  INFO [Properties.<init>]                           Java Library Path: lib
  INFO [Properties.<init>]                           Max Memory: 238616576
  INFO [Properties.<init>]                           Avaialble Processors: 4
  INFO [PropertiesBase.readFromFile]                 Reading Settings from file settings.txt
  INFO [Settings.<init>]                             Settings file not found: settings.txt (No such file or directory)
  INFO [SubstanceLoader.initLookAndFeel]             Window Skin: Default
  INFO [Main.main]                                   lpSolve: 5.5 Release 0 Build 15
  INFO [SoundPlayer.initialize]                      Initializing Sound System
  INFO [SlickLogSystem.info]                         Initialising sounds..
  INFO [SlickLogSystem.info]                         - Sound works
  INFO [SlickLogSystem.info]                         - 64 OpenAL source available
  INFO [SlickLogSystem.info]                         - Sounds source generated
  INFO [MasterClient.setServerAddress]               MasterClient: Address http://www.planetmule.com/server
  INFO [MasterClient.logSend]                        MasterClient: Sending Login
  INFO [MasterClient.apply]                          MasterClient: Session ID: u22uf06cplkltbrjcvuv9s07o2
  INFO [Login$MasterListener$1.run]                  Logged in as "LogicalDash" (id 17706)
  INFO [MetaFrame.<init>]                            Creating Meta Frame
  INFO [MapSkinParser.findSkins]                     No extra skins found
  INFO [MasterClient.logSend]                        MasterClient: Sending Enter Lobby
  INFO [Login.dispose]                               Disposing login
  INFO [Main.main]                                   Creating game container
  INFO [MuleGameContainer.<init>]                    LWJGL Version: 2.4.2
  SEVERE [Main.logError]                             java.lang.ExceptionInInitializerError
    at com.turborilla.mule.view.MuleGameContainer.<init>(MuleGameContainer.java:75)
    at com.turborilla.mule.Main.main(Main.java:170)

Per the README, here's the log_init.txt, though I don't think you'll learn much from it. There is no log.txt to show.

  INFO [Properties.<init>]                           VERSION: 1.3.6
  INFO [Properties.<init>]                           Classpath: ./data.jar
  INFO [Properties.<init>]                           Java VM: 24.45-b08
  INFO [Properties.<init>]                           Java Runtime: 1.7.0_51-b00
  INFO [Properties.<init>]                           OS: Linux 3.11.0-12-generic i386
  INFO [Properties.<init>]                           Java Library Path: lib
  INFO [Properties.<init>]                           Max Memory: 238551040
  INFO [Properties.<init>]                           Avaialble Processors: 4
  INFO [PropertiesBase.readFromFile]                 Reading Settings from file settings.txt
  INFO [Settings.<init>]                             Settings file not found: settings.txt (No such file or directory)
  INFO [SubstanceLoader.initLookAndFeel]             Window Skin: Default

I'm trying to play Planet M.U.L.E. 1.3.6 on Linux Mint 16 (64 bit... Cinnamon desktop, for all it matters) using Oracle's Java 7. I would totally use Sun's Java, like the FAQ tells me to, if it existed.

Command line says: java -jar launcher.jar nohup java -Xms64m -Xmx256m -Djava.library.path=lib -jar data.jar

I can apparently log in just fine. But as I gaze upon the lobby screen, too soon for it to populate with games open nor in progress, I get a small "Planet M.U.L.E. Error" box above, saying "ExceptionInitializerError null".

It appears whether or not I log in. I can't play locally, either. And, actually, it doesn't seem to matter whose Java I use.

Somewhere in the How-To-Play page, it should say how to sell things to the store. Right now it says how to sell MULEs back to the store, but not any of the resources.