What to do when this type of error Comes?

LimeWire version 4.15.3
Java version 1.6.0-oem from Sun Microsystems Inc.
Windows Vista v. 6.0 on x86
Free/total memory: 31334296/33357824
com.limegroup.gnutella.gui.GUILoader$StartupFailed Exception: invalid xml.war
at com.limegroup.gnutella.gui.GUILoader.sanityCheck(G UILoader.java:281)
at com.limegroup.gnutella.gui.GUILoader.load(GUILoade r.java:57)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Nativ e Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknow n Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Un known Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.limegroup.gnutella.gui.Main.main(Main.java:44)
STARTUP ERROR!