NPE in web

I really do not remember what I did to get this, but I managed to do it at least twice.

14:38:05,710 WARN [jbossweb] WARNING: Exception for /secure/admin/jira/EditAppl
icationProperties.jspa
java.lang.NullPointerException
at com.opensymphony.util.TextUtils.verifyUrl(TextUtils.java:164)
at com.atlassian.jira.web.action.admin.EditApplicationProperties.doValid
ation(EditApplicationProperties.java:101)
at webwork.action.ActionSupport.validate(ActionSupport.java:336)
at webwork.action.ActionSupport.execute(ActionSupport.java:107)
at webwork.dispatcher.ServletDispatcher.service(ServletDispatcher.java:2
61)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:344
)
at org.mortbay.jetty.servlet.WebApplicationHandler$Chain.doFilter(WebApp
licationHandler.java:361)
at com.opensymphony.module.sitemesh.filter.PageFilter.parsePage(Unknown
Source)
at com.opensymphony.module.sitemesh.filter.PageFilter.doFilter(Unknown S
ource)
at org.mortbay.jetty.servlet.WebApplicationHandler$Chain.doFilter(WebApp
licationHandler.java:353)
at com.atlassian.jira.web.security.SecurityFilter.doFilter(SecurityFilte
r.java:185)
at org.mortbay.jetty.servlet.WebApplicationHandler$Chain.doFilter(WebApp
licationHandler.java:353)
at com.atlassian.jira.web.security.LoginFilter.doFilter(LoginFilter.java
:194)
at org.mortbay.jetty.servlet.WebApplicationHandler$Chain.doFilter(WebApp
licationHandler.java:353)
at com.atlassian.jira.web.filters.EncodingFilter.doFilter(EncodingFilter
.java:29)
at org.mortbay.jetty.servlet.WebApplicationHandler$Chain.doFilter(WebApp
licationHandler.java:353)
at org.mortbay.jetty.servlet.WebApplicationHandler.dispatch(WebApplicati
onHandler.java:305)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:5
54)
at org.mortbay.jetty.servlet.WebApplicationHandler.handle(WebApplication
Handler.java:199)
at org.mortbay.http.HttpContext.handle(HttpContext.java:1572)
at org.mortbay.http.HttpContext.handle(HttpContext.java:1522)
at org.mortbay.http.HttpServer.service(HttpServer.java:795)
at org.jboss.jetty.Jetty.service(Jetty.java:531)
at org.mortbay.http.HttpConnection.service(HttpConnection.java:784)
at org.mortbay.http.HttpConnection.handleNext(HttpConnection.java:941)
at org.mortbay.http.HttpConnection.handle(HttpConnection.java:799)
at org.mortbay.http.SocketListener.handleConnection(SocketListener.java:
186)
at org.mortbay.util.ThreadedServer.handle(ThreadedServer.java:322)
at org.mortbay.util.ThreadPool$JobRunner.run(ThreadPool.java:716)
at java.lang.Thread.run(Thread.java:484)