After a few hours, I finally got a tree to be saved as a .schematic file and from there to be converted to .bo2 using a Ruby script. Now, when I attempt spawning it, I get this error ingame:
"BO2 not found in world directory. Searching in global directory.
An internal error occured while attempting to perform this command"

Error log from console:

2012-12-30 20:29:24 [SEVERE] null
org.bukkit.command.CommandException: Unhandled exception executing command 'tc' in plugin TerrainControl v2.3.6
at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46)
at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:186)
at org.bukkit.craftbukkit.v1_4_6.CraftServer.dispatchCommand(CraftServer.java:510)
at net.minecraft.server.v1_4_6.PlayerConnection.handleCommand(PlayerConnection.java:980)
at net.minecraft.server.v1_4_6.PlayerConnection.chat(PlayerConnection.java:898)
at net.minecraft.server.v1_4_6.PlayerConnection.a(PlayerConnection.java:853)
at net.minecraft.server.v1_4_6.Packet3Chat.handle(Packet3Chat.java:44)
at net.minecraft.server.v1_4_6.NetworkManager.b(NetworkManager.java:290)
at net.minecraft.server.v1_4_6.PlayerConnection.d(PlayerConnection.java:112)
at net.minecraft.server.v1_4_6.ServerConnection.b(SourceFile:39)
at net.minecraft.server.v1_4_6.DedicatedServerConnection.b(SourceFile:30)
at net.minecraft.server.v1_4_6.MinecraftServer.r(MinecraftServer.java:598)
at net.minecraft.server.v1_4_6.DedicatedServer.r(DedicatedServer.java:224)
at net.minecraft.server.v1_4_6.MinecraftServer.q(MinecraftServer.java:494)
at net.minecraft.server.v1_4_6.MinecraftServer.run(MinecraftServer.java:427)
at net.minecraft.server.v1_4_6.ThreadServerApplication.run(SourceFile:849)
Caused by: java.lang.NullPointerException
at com.khorn.terraincontrol.customobjects.CustomObjectGen.GenerateCustomObject(CustomObjectGen.java:144)
at com.khorn.terraincontrol.bukkit.commands.SpawnCommand.onCommand(SpawnCommand.java:63)
at com.khorn.terraincontrol.bukkit.commands.TCCommandExecutor.onCommand(TCCommandExecutor.java:45)
at com.khorn.terraincontrol.bukkit.TCPlugin.onCommand(TCPlugin.java:65)
at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44)
... 15 more

When I moved the BO2 to the world directory, same thing happend. When I ended it with .bo2, TerrainControl couldn't find the file. Though it exists there, and I've tried both restarting it completely and just reloading, it still doesnt work. What is wrong?

The BO2 contains a simple hand-made small tree.

Duplicate of #113.

Oh, thank you. I hope you fix this, and I'm glad it's a plugin error and not a compiling error as this is my first BO2 compiling. I'd really like to get using the plugin :)