Error on lookup Command

[DevJoey]

org.bukkit.command.CommandException: Unhandled exception executing command 'plugman' in plugin PlugMan v2.1.4
at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46) ~[spigot-1-8-8.jar:git-Spigot-db6de12-18fbb24]
at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:141) ~[spigot-1-8-8.jar:git-Spigot-db6de12-18fbb24]
at org.bukkit.craftbukkit.v1_8_R3.CraftServer.dispatchCommand(CraftServer.java:641) ~[spigot-1-8-8.jar:git-Spigot-db6de12-18fbb24]
at net.minecraft.server.v1_8_R3.PlayerConnection.handleCommand(PlayerConnection.java:1162) [spigot-1-8-8.jar:git-Spigot-db6de12-18fbb24]
at net.minecraft.server.v1_8_R3.PlayerConnection.a(PlayerConnection.java:997) [spigot-1-8-8.jar:git-Spigot-db6de12-18fbb24]
at net.minecraft.server.v1_8_R3.PacketPlayInChat.a(PacketPlayInChat.java:45) [spigot-1-8-8.jar:git-Spigot-db6de12-18fbb24]
at net.minecraft.server.v1_8_R3.PacketPlayInChat.a(PacketPlayInChat.java:1) [spigot-1-8-8.jar:git-Spigot-db6de12-18fbb24]
at net.minecraft.server.v1_8_R3.PlayerConnectionUtils$1.run(SourceFile:13) [spigot-1-8-8.jar:git-Spigot-db6de12-18fbb24]
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_191]
at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_191]
at net.minecraft.server.v1_8_R3.SystemUtils.a(SourceFile:44) [spigot-1-8-8.jar:git-Spigot-db6de12-18fbb24]
at net.minecraft.server.v1_8_R3.MinecraftServer.B(MinecraftServer.java:715) [spigot-1-8-8.jar:git-Spigot-db6de12-18fbb24]
at net.minecraft.server.v1_8_R3.DedicatedServer.B(DedicatedServer.java:374) [spigot-1-8-8.jar:git-Spigot-db6de12-18fbb24]
at net.minecraft.server.v1_8_R3.MinecraftServer.A(MinecraftServer.java:654) [spigot-1-8-8.jar:git-Spigot-db6de12-18fbb24]
at net.minecraft.server.v1_8_R3.MinecraftServer.run(MinecraftServer.java:557) [spigot-1-8-8.jar:git-Spigot-db6de12-18fbb24]
at java.lang.Thread.run(Thread.java:748) [?:1.8.0_191]
Caused by: java.lang.ClassCastException: java.lang.Integer cannot be cast to java.lang.String
at com.rylinaux.plugman.util.PluginUtil.findByCommand(PluginUtil.java:263) ~[PlugMan.jar:?]
at com.rylinaux.plugman.command.LookupCommand.execute(LookupCommand.java:108) ~[PlugMan.jar:?]
at com.rylinaux.plugman.PlugManCommandHandler.onCommand(PlugManCommandHandler.java:95) ~[PlugMan.jar:?]
at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44) ~[spigot-1-8-8.jar:git-Spigot-db6de12-18fbb24]
... 15 more