NullPointerException when searching for users via the Manage User Administration screen

When using the "Administration Console | Manage User" search functionality on cac, the following exception is generated regardless of what data is entered.

[ERROR] Wed Dec 21 23:10:02 CST 2005 [com.opensymphony.webwork.dispatcher.ServletDispatcher] Could not execute action
Throwable:
java.lang.NullPointerException
at com.opensymphony.user.User.(User.java:53)
at com.atlassian.user.impl.osuser.OSUUserManager.getUsers(OSUUserManager.java:50)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at org.springframework.aop.framework.AopProxyUtils.invokeJoinpointUsingReflection(AopProxyUtils.java:61)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:149)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:116)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:56)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:138)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:152)