Bukkit

2012-10-30 15:06:13 [SEVERE] Error occurred while enabling UsefulVillagers v0.4.0 (Is it up to date?)
java.lang.NoClassDefFoundError: com/google/gson/GsonBuilder
    at org.randomgd.bukkit.workers.WorkerHandler.getWorkerInfoFromDisk(WorkerHandler.java:350)
    at org.randomgd.bukkit.workers.WorkerHandler.onEnable(WorkerHandler.java:194)
    at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:217)
    at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:374)
    at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:381)
    at org.bukkit.craftbukkit.CraftServer.loadPlugin(CraftServer.java:270)
    at org.bukkit.craftbukkit.CraftServer.enablePlugins(CraftServer.java:252)
    at net.minecraft.server.MinecraftServer.j(MinecraftServer.java:311)
    at net.minecraft.server.MinecraftServer.e(MinecraftServer.java:290)
    at net.minecraft.server.MinecraftServer.a(MinecraftServer.java:249)
    at net.minecraft.server.DedicatedServer.init(DedicatedServer.java:141)
    at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:391)
    at net.minecraft.server.ThreadServerApplication.run(SourceFile:818)
Caused by: java.lang.ClassNotFoundException: com.google.gson.GsonBuilder
    at java.net.URLClassLoader$1.run(Unknown Source)
    at java.net.URLClassLoader$1.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(Unknown Source)
    at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:44)
    at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:29)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    ... 13 more

As pointed in the plugin manual, don't forget to download GSON, put it in a directory with the other 3rd party library (if any) and modify your server launching script with the correct -Djava.ext.dirs option.

For example: java -Xmx2048M -Xms2048M -Djava.ext.dirs=$JAVA_EXT_DIRS:/path/to/my/thirdpartylibs -jar craftbukkit.jar

Not everyone has access to how their server boots up with purchased minecraft servers, or the access to install GSON. Most purchased minecraft server services basically have a "start" and "stop" button to run the server.

Owners of servers may know how to drop in plugins to their server's plugin folders, but have no idea what you mean by lib folders or changing the boot up commands.

Is there a more plugin-friendly way to install this?

@softvelvet: Go

I see your point here. A lot of plugins (using GSON) are receiving similar tickets for the very same reasons. Maybe minecraft server host should update and not just be java server farm ...

Well, I'll look for a solution to make it handy. Perhaps include the GSON library source in my own (as it's not that big).