Bukkit

What steps will reproduce the problem?
1.  Add plugin, start server
2.
3.

What is the expected output? What do you see instead?
No errors.  The errors in the log below.
Also, even though I downloaded 2.6 (multiple times to be sure) it still reports as 2.5.
(http://dev.bukkit.org/bukkit-plugins/minecartmania-reborn/files/25-minecart-mania-2-6/)

What version of the product are you using?
MinecartMania 2.6
craftbukkit-1.7.9-R0.2.jar

Do you have an error log of what happened?

8:10:25 PM [SEVERE] Could not pass event VehicleUpdateEvent to MinecartMania v2.5
8:10:25 PM org.bukkit.event.EventException
8:10:25 PM     at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:294) ~[craftbukkit-1.7.9-R0.2.jar:git-Bukkit-1.7.9-R0.1-10-g8688bd4-b3092jnks]
8:10:25 PM     at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[craftbukkit-1.7.9-R0.2.jar:git-Bukkit-1.7.9-R0.1-10-g8688bd4-b3092jnks]
8:10:25 PM     at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:501) [craftbukkit-1.7.9-R0.2.jar:git-Bukkit-1.7.9-R0.1-10-g8688bd4-b3092jnks]
8:10:25 PM     at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:486) [craftbukkit-1.7.9-R0.2.jar:git-Bukkit-1.7.9-R0.1-10-g8688bd4-b3092jnks]
8:10:25 PM     at net.minecraft.server.v1_7_R3.EntityMinecartAbstract.h(EntityMinecartAbstract.java:319) [craftbukkit-1.7.9-R0.2.jar:git-Bukkit-1.7.9-R0.1-10-g8688bd4-b3092jnks]
8:10:25 PM     at net.minecraft.server.v1_7_R3.World.entityJoinedWorld(World.java:1421) [craftbukkit-1.7.9-R0.2.jar:git-Bukkit-1.7.9-R0.1-10-g8688bd4-b3092jnks]
8:10:25 PM     at net.minecraft.server.v1_7_R3.World.playerJoinedWorld(World.java:1402) [craftbukkit-1.7.9-R0.2.jar:git-Bukkit-1.7.9-R0.1-10-g8688bd4-b3092jnks]
8:10:25 PM     at net.minecraft.server.v1_7_R3.World.tickEntities(World.java:1290) [craftbukkit-1.7.9-R0.2.jar:git-Bukkit-1.7.9-R0.1-10-g8688bd4-b3092jnks]
8:10:25 PM     at net.minecraft.server.v1_7_R3.WorldServer.tickEntities(WorldServer.java:481) [craftbukkit-1.7.9-R0.2.jar:git-Bukkit-1.7.9-R0.1-10-g8688bd4-b3092jnks]
8:10:25 PM     at net.minecraft.server.v1_7_R3.MinecraftServer.v(MinecraftServer.java:649) [craftbukkit-1.7.9-R0.2.jar:git-Bukkit-1.7.9-R0.1-10-g8688bd4-b3092jnks]
8:10:25 PM     at net.minecraft.server.v1_7_R3.DedicatedServer.v(DedicatedServer.java:260) [craftbukkit-1.7.9-R0.2.jar:git-Bukkit-1.7.9-R0.1-10-g8688bd4-b3092jnks]
8:10:25 PM     at net.minecraft.server.v1_7_R3.MinecraftServer.u(MinecraftServer.java:558) [craftbukkit-1.7.9-R0.2.jar:git-Bukkit-1.7.9-R0.1-10-g8688bd4-b3092jnks]
8:10:25 PM     at net.minecraft.server.v1_7_R3.MinecraftServer.run(MinecraftServer.java:469) [craftbukkit-1.7.9-R0.2.jar:git-Bukkit-1.7.9-R0.1-10-g8688bd4-b3092jnks]
8:10:25 PM     at net.minecraft.server.v1_7_R3.ThreadServerApplication.run(SourceFile:628) [craftbukkit-1.7.9-R0.2.jar:git-Bukkit-1.7.9-R0.1-10-g8688bd4-b3092jnks]
8:10:25 PM Caused by: java.lang.NoClassDefFoundError: net/minecraft/server/v1_7_R4/World
8:10:25 PM     at com.afforess.minecartmania.entity.MinecartManiaWorld.CreateMMMinecart(MinecartManiaWorld.java:84) ~[?:?]
8:10:25 PM     at com.afforess.minecartmania.listeners.CoreListener.onVehicleUpdate(CoreListener.java:42) ~[?:?]
8:10:25 PM     at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.7.0_25]
8:10:25 PM     at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.7.0_25]
8:10:25 PM     at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.7.0_25]
8:10:25 PM     at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.7.0_25]
8:10:25 PM     at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:292) ~[craftbukkit-1.7.9-R0.2.jar:git-Bukkit-1.7.9-R0.1-10-g8688bd4-b3092jnks]

Please provide any additional information below.

I have the same problem.