Bukkit

2nd /rankup plugin with the same error!
Here is the console when error occurred!
27.12 00:58:58 [Server] INFO at ru.tehkode.permissions.ProxyPermissionGroup.initialize(ProxyPermissionGroup.java:43) ~[?:?]
27.12 00:58:58 [Server] INFO at ru.tehkode.permissions.PermissionGroup.initialize(PermissionGroup.java:42) ~[?:?]
27.12 00:58:58 [Server] INFO at ru.tehkode.permissions.PermissionEntity.initialize(PermissionEntity.java:53) ~[?:?]
27.12 00:58:58 [Server] INFO at ru.tehkode.permissions.PermissionEntity.getOptionBoolean(PermissionEntity.java:294) ~[?:?]
27.12 00:58:58 [Server] INFO at ru.tehkode.permissions.PermissionGroup.getOption(PermissionGroup.java:651) ~[?:?]
27.12 00:58:58 [Server] INFO at ru.tehkode.permissions.PermissionGroup.getOption(PermissionGroup.java:655) ~[?:?]
27.12 00:58:58 [Server] INFO at ru.tehkode.permissions.ProxyPermissionGroup.getOwnOption(ProxyPermissionGroup.java:102) ~[?:?]
27.12 00:58:58 [Server] INFO at ru.tehkode.permissions.backends.file.FileEntity.getOption(FileEntity.java:126) ~[?:?]
27.12 00:58:58 [Server] INFO at org.bukkit.configuration.MemorySection.getString(MemorySection.java:285) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
27.12 00:58:58 [Server] INFO at org.bukkit.configuration.MemorySection.get(MemorySection.java:219) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
27.12 00:58:58 [Server] INFO at org.bukkit.configuration.MemorySection.getConfigurationSection(MemorySection.java:679) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
27.12 00:58:58 [Server] INFO at org.bukkit.configuration.MemorySection.get(MemorySection.java:202) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
27.12 00:58:58 [Server] INFO Caused by: java.lang.StackOverflowError
27.12 00:58:58 [Server] INFO at net.minecraft.server.v1_7_R1.ThreadServerApplication.run(SourceFile:617) [craftbukkit.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
27.12 00:58:58 [Server] INFO at net.minecraft.server.v1_7_R1.MinecraftServer.run(MinecraftServer.java:457) [craftbukkit.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
27.12 00:58:58 [Server] INFO at net.minecraft.server.v1_7_R1.MinecraftServer.t(MinecraftServer.java:545) [craftbukkit.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
27.12 00:58:58 [Server] INFO at net.minecraft.server.v1_7_R1.DedicatedServer.u(DedicatedServer.java:250) [craftbukkit.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
27.12 00:58:58 [Server] INFO at net.minecraft.server.v1_7_R1.MinecraftServer.u(MinecraftServer.java:655) [craftbukkit.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
27.12 00:58:58 [Server] INFO at net.minecraft.server.v1_7_R1.ServerConnection.c(SourceFile:134) [craftbukkit.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
27.12 00:58:58 [Server] INFO at net.minecraft.server.v1_7_R1.NetworkManager.a(NetworkManager.java:146) [craftbukkit.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
27.12 00:58:58 [Server] INFO at net.minecraft.server.v1_7_R1.PacketPlayInChat.handle(PacketPlayInChat.java:47) [craftbukkit.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
27.12 00:58:58 [Server] INFO at net.minecraft.server.v1_7_R1.PacketPlayInChat.a(PacketPlayInChat.java:28) [craftbukkit.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
27.12 00:58:58 [Server] INFO at net.minecraft.server.v1_7_R1.PlayerConnection.a(PlayerConnection.java:814) [craftbukkit.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
27.12 00:58:58 [Server] INFO at net.minecraft.server.v1_7_R1.PlayerConnection.handleCommand(PlayerConnection.java:932) [craftbukkit.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
27.12 00:58:58 [Server] INFO at org.bukkit.craftbukkit.v1_7_R1.CraftServer.dispatchCommand(CraftServer.java:542) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
27.12 00:58:58 [Server] INFO at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:196) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
27.12 00:58:58 [Server] INFO at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.2-b2974jnks]
27.12 00:58:58 [Server] INFO org.bukkit.command.CommandException: Unhandled exception executing command 'rankup' in plugin Rankup v1.2
27.12 00:58:58 [Server] ERROR null