Erro v_Rankup

[19:45:35 ERROR]: Could not pass event PlayerInteractEntityEvent to V_RankUP v1.0
org.bukkit.event.EventException
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:310) ~[Spigot.jar:git-Spigot-db6de12-18fbb24]
        at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[Spigot.jar:git-Spigot-db6de12-18fbb24]
        at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:502) [Spigot.jar:git-Spigot-db6de12-18fbb24]
        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:487) [Spigot.jar:git-Spigot-db6de12-18fbb24]
        at net.minecraft.server.v1_8_R3.PlayerConnection.a(PlayerConnection.java:1315) [Spigot.jar:git-Spigot-db6de12-18fbb24]
        at net.minecraft.server.v1_8_R3.PacketPlayInUseEntity.a(SourceFile:52) [Spigot.jar:git-Spigot-db6de12-18fbb24]
        at net.minecraft.server.v1_8_R3.PacketPlayInUseEntity.a(SourceFile:11) [Spigot.jar:git-Spigot-db6de12-18fbb24]
        at net.minecraft.server.v1_8_R3.PlayerConnectionUtils$1.run(SourceFile:13) [Spigot.jar:git-Spigot-db6de12-18fbb24]
        at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) [?:1.8.0_162]
        at java.util.concurrent.FutureTask.run(Unknown Source) [?:1.8.0_162]
        at net.minecraft.server.v1_8_R3.SystemUtils.a(SourceFile:44) [Spigot.jar:git-Spigot-db6de12-18fbb24]
        at net.minecraft.server.v1_8_R3.MinecraftServer.B(MinecraftServer.java:715) [Spigot.jar:git-Spigot-db6de12-18fbb24]
        at net.minecraft.server.v1_8_R3.DedicatedServer.B(DedicatedServer.java:374) [Spigot.jar:git-Spigot-db6de12-18fbb24]
        at net.minecraft.server.v1_8_R3.MinecraftServer.A(MinecraftServer.java:654) [Spigot.jar:git-Spigot-db6de12-18fbb24]
        at net.minecraft.server.v1_8_R3.MinecraftServer.run(MinecraftServer.java:557) [Spigot.jar:git-Spigot-db6de12-18fbb24]
        at java.lang.Thread.run(Unknown Source) [?:1.8.0_162]
Caused by: java.lang.NullPointerException
        at java.lang.String.replace(Unknown Source) ~[?:1.8.0_162]
        at com.victor696.rankup.Metodos.rankupingInGui(Metodos.java:165) ~[?:?]
        at com.victor696.rankup.Listeners.Listeners.PlayerInteractEntityEvent(Listeners.java:53) ~[?:?]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_162]
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_162]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_162]
        at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_162]
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:306) ~[Spigot.jar:git-Spigot-db6de12-18fbb24]
        ... 15 more