Problem/Bug Help! Tekkit Classic Server

I am Trying to Set Up a Tekkit Classic Bukkit server for me and my friend but I got this error message in my launch.BAT file

09:22:09 [SEVERE] Unexpected exception
java.lang.RuntimeException: Failed to check session lock, aborting
at net.minecraft.server.WorldNBTStorage.f(WorldNBTStorage.java:53)
at net.minecraft.server.WorldNBTStorage.<init>(WorldNBTStorage.java:38)
at net.minecraft.server.ServerNBTManager.<init>(ServerNBTManager.java:9)

at net.minecraft.server.MinecraftServer.a(MinecraftServer.java:276)
at net.minecraft.server.MinecraftServer.init(MinecraftServer.java:208)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:438)
at net.minecraft.server.ThreadServerApplication.run(SourceFile:492)
09:22:10 [WARNING] Could not get information about this CraftBukkit version; per
haps you are running a custom one?: FileNotFoundException
09:22:10 [WARNING] Could not get latest artifact information: FileNotFoundExcept
ion
>

 

Make sure your world does not contain the session.lock file. If it it does then you should delete it.