error

[18:08:09 ERROR]: Error occurred while enabling PlotContest v1.0.6 (Is it up to date?)
java.lang.IllegalArgumentException: The permission plotcontest.enter is already defined!
        at org.bukkit.plugin.SimplePluginManager.addPermission(SimplePluginManager.java:599) ~[spigot-1.11.2.jar:git-Spigot-625bc00-186c351]
        at me.jwonacy.PlotContests.onEnable(PlotContests.java:40) ~[plotcontest.jar:?]
        at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:271) ~[spigot-1.11.2.jar:git-Spigot-625bc00-186c351]
        at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:337) [spigot-1.11.2.jar:git-Spigot-625bc00-186c351]
        at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:405) [spigot-1.11.2.jar:git-Spigot-625bc00-186c351]
        at com.rylinaux.plugman.util.PluginUtil.load(PluginUtil.java:366) [PlugMan.jar:?]
        at com.rylinaux.plugman.command.LoadCommand.execute(LoadCommand.java:114) [PlugMan.jar:?]
        at com.rylinaux.plugman.PlugManCommandHandler.onCommand(PlugManCommandHandler.java:95) [PlugMan.jar:?]
        at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44) [spigot-1.11.2.jar:git-Spigot-625bc00-186c351]
        at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:141) [spigot-1.11.2.jar:git-Spigot-625bc00-186c351]
        at org.bukkit.craftbukkit.v1_11_R1.CraftServer.dispatchCommand(CraftServer.java:650) [spigot-1.11.2.jar:git-Spigot-625bc00-186c351]
        at org.bukkit.craftbukkit.v1_11_R1.CraftServer.dispatchServerCommand(CraftServer.java:636) [spigot-1.11.2.jar:git-Spigot-625bc00-186c351]
        at net.minecraft.server.v1_11_R1.DedicatedServer.aM(DedicatedServer.java:437) [spigot-1.11.2.jar:git-Spigot-625bc00-