Towny Error - some commands not working = 'internal error'

2012-01-05 23:49:48 [SEVERE] null
org.bukkit.command.CommandException: Unhandled exception executing command 't' in plugin Essentials v2.7.1
	at org.bukkit.command.PluginCommand.execute(PluginCommand.java:42)
	at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:165)
	at org.bukkit.craftbukkit.CraftServer.dispatchCommand(CraftServer.java:378)
	at net.minecraft.server.NetServerHandler.handleCommand(NetServerHandler.java:757)
	at net.minecraft.server.NetServerHandler.chat(NetServerHandler.java:722)
	at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:715)
	at net.minecraft.server.Packet3Chat.a(Packet3Chat.java:33)
	at net.minecraft.server.NetworkManager.b(NetworkManager.java:226)
	at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:93)
	at net.minecraft.server.NetworkListenThread.a(SourceFile:108)
	at net.minecraft.server.MinecraftServer.w(MinecraftServer.java:527)
	at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:425)
	at net.minecraft.server.ThreadServerApplication.run(SourceFile:457)
Caused by: org.bukkit.command.CommandException: Unhandled exception executing command 't' in plugin Towny v0.78.0.0
	at org.bukkit.command.PluginCommand.execute(PluginCommand.java:42)
	at com.earth2me.essentials.Essentials.onCommandEssentials(Essentials.java:303)
	at com.earth2me.essentials.Essentials.onCommand(Essentials.java:290)
	at org.bukkit.command.PluginCommand.execute(PluginCommand.java:40)
	... 12 more
Caused by: java.lang.IncompatibleClassChangeError: Expected static method com.nijikokun.register.payment.Methods.getMethod()Lcom/nijikokun/register/payment/Method;
	at com.palmergames.bukkit.towny.object.TownyEconomyObject.getEconomyAccount(TownyEconomyObject.java:175)
	at com.palmergames.bukkit.towny.object.TownyEconomyObject.getHoldingBalance(TownyEconomyObject.java:147)
	at com.palmergames.bukkit.towny.object.TownyEconomyObject.canPayFromHoldings(TownyEconomyObject.java:207)
	at com.palmergames.bukkit.towny.command.TownCommand.checkIfSelectionIsValid(TownCommand.java:1723)
	at com.palmergames.bukkit.towny.command.TownCommand.parseTownClaimCommand(TownCommand.java:1591)
	at com.palmergames.bukkit.towny.command.TownCommand.parseTownCommand(TownCommand.java:168)
	at com.palmergames.bukkit.towny.command.TownCommand.onCommand(TownCommand.java:93)
	at org.bukkit.command.PluginCommand.execute(PluginCommand.java:40)
	... 15 more
2012-01-05 23:49:56 [INFO] [PLAYER_COMMAND] robertsno2: /t
2012-01-05 23:49:56 [SEVERE] null
org.bukkit.command.CommandException: Unhandled exception executing command 't' in plugin Essentials v2.7.1
	at org.bukkit.command.PluginCommand.execute(PluginCommand.java:42)
	at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:165)
	at org.bukkit.craftbukkit.CraftServer.dispatchCommand(CraftServer.java:378)
	at net.minecraft.server.NetServerHandler.handleCommand(NetServerHandler.java:757)
	at net.minecraft.server.NetServerHandler.chat(NetServerHandler.java:722)
	at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:715)
	at net.minecraft.server.Packet3Chat.a(Packet3Chat.java:33)
	at net.minecraft.server.NetworkManager.b(NetworkManager.java:226)
	at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:93)
	at net.minecraft.server.NetworkListenThread.a(SourceFile:108)
	at net.minecraft.server.MinecraftServer.w(MinecraftServer.java:527)
	at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:425)
	at net.minecraft.server.ThreadServerApplication.run(SourceFile:457)
Caused by: org.bukkit.command.CommandException: Unhandled exception executing command 't' in plugin Towny v0.78.0.0
	at org.bukkit.command.PluginCommand.execute(PluginCommand.java:42)
	at com.earth2me.essentials.Essentials.onCommandEssentials(Essentials.java:303)
	at com.earth2me.essentials.Essentials.onCommand(Essentials.java:290)
	at org.bukkit.command.PluginCommand.execute(PluginCommand.java:40)
	... 12 more
Caused by: java.lang.IncompatibleClassChangeError: Expected static method com.nijikokun.register.payment.Methods.getMethod()Lcom/nijikokun/register/payment/Method;
	at com.palmergames.bukkit.towny.object.TownyEconomyObject.getEconomyAccount(TownyEconomyObject.java:175)
	at com.palmergames.bukkit.towny.object.TownyEconomyObject.getHoldingBalance(TownyEconomyObject.java:147)
	at com.palmergames.bukkit.towny.object.TownyEconomyObject.getHoldingFormattedBalance(TownyEconomyObject.java:237)
	at com.palmergames.bukkit.towny.TownyFormatter.getStatus(TownyFormatter.java:150)
	at com.palmergames.bukkit.towny.object.TownyUniverse.getStatus(TownyUniverse.java:873)
	at com.palmergames.bukkit.towny.command.TownCommand.parseTownCommand(TownCommand.java:107)
	at com.palmergames.bukkit.towny.command.TownCommand.onCommand(TownCommand.java:93)
	at org.bukkit.command.PluginCommand.execute(PluginCommand.java:40)
	... 15 more