[19:44:30] [Server thread/INFO]: NLBlackEagle issued server command: /butcher
[19:44:30] [Server thread/WARN]: [Sentry] Task #641 for Sentry v1.8.2 generated an exception
java.lang.ClassCastException: net.citizensnpcs.npc.entity.SpiderController$SpiderNPC cannot be cast to org.bukkit.entity.Horse
    at net.aufdemrand.sentry.SentryInstance.createMount(SentryInstance.java:1902) ~[?:?]
    at net.aufdemrand.sentry.SentryInstance.mount(SentryInstance.java:1846) ~[?:?]
    at net.aufdemrand.sentry.SentryInstance$SentryLogic.run(SentryInstance.java:1428) ~[?:?]
    at org.bukkit.craftbukkit.v1_7_R4.scheduler.CraftTask.run(CraftTask.java:71) ~[spigot.jar:git-Spigot-1604]
    at org.bukkit.craftbukkit.v1_7_R4.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:350) [spigot.jar:git-Spigot-1604]
    at net.minecraft.server.v1_7_R4.MinecraftServer.v(MinecraftServer.java:641) [spigot.jar:git-Spigot-1604]
    at net.minecraft.server.v1_7_R4.DedicatedServer.v(DedicatedServer.java:289) [spigot.jar:git-Spigot-1604]
    at net.minecraft.server.v1_7_R4.MinecraftServer.u(MinecraftServer.java:584) [spigot.jar:git-Spigot-1604]
    at net.minecraft.server.v1_7_R4.MinecraftServer.run(MinecraftServer.java:490) [spigot.jar:git-Spigot-1604]
    at net.minecraft.server.v1_7_R4.ThreadServerApplication.run(SourceFile:628) [spigot.jar:git-Spigot-1604]
[19:44:30] [Server thread/INFO]: [Server] Server is restarting. World is being saved.