[18:29:01 WARN]: [Quests] Task #4928 for Quests v3.4.5-b524 generated an exception
java.lang.NullPointerException
        at me.blackvein.quests.NpcEffectThread.run(NpcEffectThread.java:51) ~[Quests-3.4.5.jar:?]
        at org.bukkit.craftbukkit.v1_9_R2.scheduler.CraftTask.run(CraftTask.java:71) ~[spigot1.9.4.jar:git-Spigot-c6871e2-0cd0397]
        at org.bukkit.craftbukkit.v1_9_R2.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:350) [spigot1.9.4.jar:git-Spigot-c6871e2-0cd0397]
        at net.minecraft.server.v1_9_R2.MinecraftServer.D(MinecraftServer.java:734) [spigot1.9.4.jar:git-Spigot-c6871e2-0cd0397]
        at net.minecraft.server.v1_9_R2.DedicatedServer.D(DedicatedServer.java:399) [spigot1.9.4.jar:git-Spigot-c6871e2-0cd0397]
        at net.minecraft.server.v1_9_R2.MinecraftServer.C(MinecraftServer.java:665) [spigot1.9.4.jar:git-Spigot-c6871e2-0cd0397]
        at net.minecraft.server.v1_9_R2.MinecraftServer.run(MinecraftServer.java:564) [spigot1.9.4.jar:git-Spigot-c6871e2-0cd0397]
        at java.lang.Thread.run(Thread.java:748) [?:1.8.0_191]