CB++ and Heroes Error

00:50:49 [INFO] [Heroes] Enabling Heroes v1.4.8-b1474
00:50:49 [SEVERE] [Heroes] You're attempting to run Heroes on an incompatible version of CraftBukkit!
00:50:49 [SEVERE] [Heroes] This version of Heroes is compatible at the minimum with: CraftBukkit b1988jnks or CraftBukkit++ 131
00:50:49 [INFO] [Heroes] Disabling Heroes v1.4.8-b1474
00:50:49 [SEVERE] Error occurred while disabling Heroes v1.4.8-b1474 (Is it up to date?)
java.lang.NullPointerException
        at com.herocraftonline.heroes.Heroes.onDisable(Heroes.java:181)
        at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:217)
        at org.bukkit.plugin.java.JavaPluginLoader.disablePlugin(JavaPluginLoader.java:362)
        at org.bukkit.plugin.SimplePluginManager.disablePlugin(SimplePluginManager.java:401)
        at com.herocraftonline.heroes.Heroes.onEnable(Heroes.java:195)
        at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:215)
        at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:336)
        at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:383)
        at org.bukkit.craftbukkit.CraftServer.loadPlugin(CraftServer.java:373)
        at org.bukkit.craftbukkit.CraftServer.enablePlugins(CraftServer.java:355)
        at net.minecraft.server.MinecraftServer.t(MinecraftServer.java:420)
        at net.minecraft.server.MinecraftServer.a(MinecraftServer.java:407)
        at net.minecraft.server.MinecraftServer.init(MinecraftServer.java:224)
        at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:475)
        at net.minecraft.server.ThreadServerApplication.run(SourceFile:492)