[14:50:47 WARN]: [Core] Task #2 for Core v1.0 generated an exception
java.lang.AbstractMethodError: me.Pinger.core.ranks.staff.Staff.compareTo(Ljava/lang/Object;)I
        at java.util.Comparators$NaturalOrderComparator.compare(Unknown Source) ~[?:1.8.0_151]
        at java.util.Comparators$NaturalOrderComparator.compare(Unknown Source) ~[?:1.8.0_151]
        at java.util.TimSort.countRunAndMakeAscending(Unknown Source) ~[?:1.8.0_151]
        at java.util.TimSort.sort(Unknown Source) ~[?:1.8.0_151]
        at java.util.Arrays.sort(Unknown Source) ~[?:1.8.0_151]
        at java.util.stream.SortedOps$SizedRefSortingSink.end(Unknown Source) ~[?:1.8.0_151]
        at java.util.stream.AbstractPipeline.copyIntoWithCancel(Unknown Source) ~[?:1.8.0_151]
        at java.util.stream.AbstractPipeline.copyInto(Unknown Source) ~[?:1.8.0_151]
        at java.util.stream.AbstractPipeline.wrapAndCopyInto(Unknown Source) ~[?:1.8.0_151]
        at java.util.stream.FindOps$FindOp.evaluateSequential(Unknown Source) ~[?:1.8.0_151]
        at java.util.stream.AbstractPipeline.evaluate(Unknown Source) ~[?:1.8.0_151]
        at java.util.stream.ReferencePipeline.findFirst(Unknown Source) ~[?:1.8.0_151]
        at me.Pinger.core.user.User.getSingularName(User.java:150) ~[?:?]
        at me.Pinger.core.scoreboard.Scoreboard.updateScoreboard(Scoreboard.java:98) ~[?:?]
        at me.Pinger.core.scoreboard.Scoreboard$1.run(Scoreboard.java:26) ~[?:?]
        at org.bukkit.craftbukkit.v1_7_R4.scheduler.CraftTask.run(CraftTask.java:71) ~[spigot.jar:git-PaperSpigot-36]
        at org.bukkit.craftbukkit.v1_7_R4.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:350) [spigot.jar:git-PaperSpigot-36]
        at net.minecraft.server.v1_7_R4.MinecraftServer.v(MinecraftServer.java:696) [spigot.jar:git-PaperSpigot-36]
        at net.minecraft.server.v1_7_R4.DedicatedServer.v(DedicatedServer.java:307) [spigot.jar:git-PaperSpigot-36]
        at net.minecraft.server.v1_7_R4.MinecraftServer.u(MinecraftServer.java:638) [spigot.jar:git-PaperSpigot-36]
        at net.minecraft.server.v1_7_R4.MinecraftServer.run(MinecraftServer.java:544) [spigot.jar:git-PaperSpigot-36]
        at net.minecraft.server.v1_7_R4.ThreadServerApplication.run(SourceFile:628) [spigot.jar:git-PaperSpigot-36]