Bukkit

What steps will reproduce the problem?
1. using mcpc-plus-1.7.2-R0.4-forge1033-B51
2. using R: ChessCraft v2.5.0 for 1.7.4 Apr 23, 2014
OR
R: ChessCraft v2.4.5 for CB 1.7.2-R0.3 Apr 04, 2014
(both gaves the same exception)

Do you have an error log of what happened?
SEVERE: Error occurred while enabling ChessCraft v2.4.5 (Is it up to date?)
java.lang.NoClassDefFoundError: net/minecraft/server/World
        at java.lang.Class.forName0(Native Method)
        at java.lang.Class.forName(Unknown Source)
        at me.desht.chesscraft.dhutils.nms.NMSHelper.init(NMSHelper.java:55)
        at me.desht.chesscraft.dhutils.nms.NMSHelper.init(NMSHelper.java:34)
        at me.desht.chesscraft.ChessCraft.onEnable(ChessCraft.java:81)
        at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:250)
        at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:360)
        at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:390)
        at org.bukkit.craftbukkit.CraftServer.loadPlugin(CraftServer.java:391)
        at org.bukkit.craftbukkit.CraftServer.enablePlugins(CraftServer.java:327)
        at net.minecraft.server.MinecraftServer.func_71243_i(MinecraftServer.java:518)
        at net.minecraft.server.MinecraftServer.func_71222_d(MinecraftServer.java:491)
        at net.minecraft.server.MinecraftServer.func_71247_a(MinecraftServer.java:434)
        at net.minecraft.server.dedicated.DedicatedServer.func_71197_b(DedicatedServer.java:292)
        at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:622)
        at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.ClassNotFoundException: net.minecraft.server.World
        at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:365)
        at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:212)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        ... 16 more

Yeah, the whole NMS abstraction system I use doesn't support MCPC+ at this time. I will have a look and see if it can be easily added, though.

Ah ok good to know . Thanks :)

Update: I know why ChessCraft won't run with MCPC+ now, and I've sort-of-fixed that - the plugin will actually enable now.

However the current versions of ChessCraft (2.5.x) require CraftBukkit 1.7.9 due to UUID changes, and I don't believe there's a 1.7.9-compatible Cauldron (formerly known as MCPC+) out at this point. If/when Cauldron releases a 1.7.9-based JAR then there's a good chance ChessCraft will work, although board drawing performance will be reduced (large board styles will not be recommended).

I'll leave this open for now so I don't forget about it, and keep an eye out for a 1.7.9 Cauldron release.

I guess there is no chance of having MCPC+ support made compatible with a 1.6.4 version of ChessCraft?

Yeah, I won't be backporting the current release to MCPC+/Cauldron 1.6.4.

However, I see that there is now a 1.7.10 Cauldron release, which might work with the current ChessCraft release. Please give it a go and let me know.