when i want to start client it gives me this error

Code:
Exception in thread "main" java.lang.NoClassDefFoundError: WorldController
        at client.setHighMem(client.java:3824)
        at client.main(client.java:3835)
Caused by: java.lang.ClassNotFoundException: WorldController
        at java.net.URLClassLoader$1.run(Unknown Source)
        at java.net.URLClassLoader$1.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        ... 2 more
Druk op een toets om door te gaan. . .
Its a [PI] client InterPK