Server crash

I'have a problem with server. Server logs:

10.02 17:57:05 [server] INFO at cpw.mods.fml.common.Loader.preModInit(Loader.java:235)

10.02 17:57:05 [server] INFO at cpw.mods.fml.common.modloader.ModLoaderModContainer.preInit(ModLoaderModContainer.java:107)

10.02 17:57:05 [server] INFO at java.lang.Class.newInstance(Unknown Source)

10.02 17:57:05 [server] INFO at java.lang.Class.getConstructor0(Unknown Source)

10.02 17:57:05 [server] INFO at java.lang.Class.privateGetDeclaredConstructors(Unknown Source)

10.02 17:57:05 [server] INFO at java.lang.Class.getDeclaredConstructors0(Native Method)

10.02 17:57:05 [server] INFO java.lang.NoClassDefFoundError: pb

10.02 17:57:05 [server] SEVERE Unexpected exception

10.02 17:57:05 [server] SEVERE ... 11 more

10.02 17:57:05 [server] SEVERE at java.lang.ClassLoader.loadClass(Unknown Source)

10.02 17:57:05 [server] SEVERE at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)

10.02 17:57:05 [server] SEVERE at java.lang.ClassLoader.loadClass(Unknown Source)

10.02 17:57:05 [server] SEVERE at java.net.URLClassLoader.findClass(Unknown Source)

10.02 17:57:05 [server] SEVERE at java.security.AccessController.doPrivileged(Native Method)

10.02 17:57:05 [server] SEVERE at java.net.URLClassLoader$1.run(Unknown Source)

10.02 17:57:05 [server] SEVERE at java.net.URLClassLoader$1.run(Unknown Source)

10.02 17:57:05 [server] SEVERE Caused by: java.lang.ClassNotFoundException: pb

10.02 17:57:05 [server] SEVERE at net.minecraft.server.ThreadServerApplication.run(SourceFile:492)

10.02 17:57:05 [server] SEVERE at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:438)

10.02 17:57:05 [server] SEVERE at net.minecraft.server.MinecraftServer.init(MinecraftServer.java:135)

10.02 17:57:05 [server] SEVERE at cpw.mods.fml.server.FMLBukkitHandler.onPreLoad(FMLBukkitHandler.java:134)

10.02 17:57:05 [server] SEVERE at cpw.mods.fml.common.Loader.loadMods(Loader.java:607)

10.02 17:57:05 [server] SEVERE at cpw.mods.fml.common.Loader.preModInit(Loader.java:235)

10.02 17:57:05 [server] SEVERE at cpw.mods.fml.common.modloader.ModLoaderModContainer.preInit(ModLoaderModContainer.java:107)

10.02 17:57:05 [server] SEVERE at java.lang.Class.newInstance(Unknown Source)

10.02 17:57:05 [server] SEVERE at java.lang.Class.getConstructor0(Unknown Source)

10.02 17:57:05 [server] SEVERE at java.lang.Class.privateGetDeclaredConstructors(Unknown Source)

10.02 17:57:05 [server] SEVERE at java.lang.Class.getDeclaredConstructors0(Native Method)

10.02 17:57:05 [server] SEVERE java.lang.NoClassDefFoundError: pb

10.02 17:57:05 [server] INFO Forge Mod Loader has loaded 28 mods

10.02 17:57:03 [server] INFO Loading mods from /mods

10.02 17:57:02 [server] INFO Forge Mod Loader version 2.2.91.173 for Minecraft 1.2.5 loading

10.02 17:57:02 [server] INFO Completed early MinecraftForge initialization

10.02 17:57:02 [server] INFO Attempting early MinecraftForge initialization

10.02 17:57:02 [server] INFO Starting minecraft server version 1.2.5