error

14:07:30 [SEVERE] Error occurred while enabling OtherDrops v2.8-beta5 (Is it up to date?)
java.lang.NullPointerException
        at com.gmail.zariust.otherdrops.drop.ItemDrop.getName(ItemDrop.java:254)
        at com.gmail.zariust.otherdrops.drop.DropType.toString(DropType.java:143)
        at java.lang.String.valueOf(String.java:2854)
        at java.lang.StringBuilder.append(StringBuilder.java:128)
        at java.util.AbstractCollection.toString(AbstractCollection.java:450)
        at com.gmail.zariust.otherdrops.drop.DropListExclusive.getName(DropListExclusive.java:145)
        at com.gmail.zariust.otherdrops.drop.DropType.toString(DropType.java:143)
        at com.gmail.zariust.otherdrops.OtherDropsConfig.loadSimpleDrop(OtherDropsConfig.java:610)
        at com.gmail.zariust.otherdrops.OtherDropsConfig.loadDrop(OtherDropsConfig.java:511)
        at com.gmail.zariust.otherdrops.OtherDropsConfig.loadBlockDrops(OtherDropsConfig.java:495)
        at com.gmail.zariust.otherdrops.OtherDropsConfig.loadDropsFile(OtherDropsConfig.java:414)
        at com.gmail.zariust.otherdrops.OtherDropsConfig.loadDropsFile(OtherDropsConfig.java:433)
        at com.gmail.zariust.otherdrops.OtherDropsConfig.loadConfig(OtherDropsConfig.java:297)
        at com.gmail.zariust.otherdrops.OtherDropsConfig.load(OtherDropsConfig.java:191)
        at com.gmail.zariust.otherdrops.OtherDrops.onEnable(OtherDrops.java:90)
        at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:217)
        at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:457)
        at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:381)
        at org.bukkit.craftbukkit.v1_4_R1.CraftServer.loadPlugin(CraftServer.java:282)
        at org.bukkit.craftbukkit.v1_4_R1.CraftServer.enablePlugins(CraftServer.java:264)
        at net.minecraft.server.v1_4_R1.MinecraftServer.j(MinecraftServer.java:321)
        at net.minecraft.server.v1_4_R1.MinecraftServer.e(MinecraftServer.java:300)
        at net.minecraft.server.v1_4_R1.MinecraftServer.a(MinecraftServer.java:259)
        at net.minecraft.server.v1_4_R1.DedicatedServer.init(DedicatedServer.java:149)
        at net.minecraft.server.v1_4_R1.MinecraftServer.run(MinecraftServer.java:399)
        at net.minecraft.server.v1_4_R1.ThreadServerApplication.run(SourceFile:849)