Error 500--Internal Server Error

java.lang.NullPointerException
	at jsp_servlet._bang_45_xep_45_hang.__tyle._jspService(__tyle.java:535)
	at weblogic.servlet.jsp.JspBase.service(JspBase.java:35)
	at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:280)
	at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:254)
	at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:136)
	at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:346)
	at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:243)
	at weblogic.servlet.internal.RequestDispatcherImpl.invokeServlet(RequestDispatcherImpl.java:587)
	at weblogic.servlet.internal.RequestDispatcherImpl.forward(RequestDispatcherImpl.java:273)
	at org.tuckey.web.filters.urlrewrite.NormalRewrittenUrl.doRewrite(NormalRewrittenUrl.java:213)
	at org.tuckey.web.filters.urlrewrite.RuleChain.handleRewrite(RuleChain.java:171)
	at org.tuckey.web.filters.urlrewrite.RuleChain.doRules(RuleChain.java:145)
	at org.tuckey.web.filters.urlrewrite.UrlRewriter.processRequest(UrlRewriter.java:92)
	at org.tuckey.web.filters.urlrewrite.UrlRewriteFilter.doFilter(UrlRewriteFilter.java:381)
	at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:79)
	at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.wrapRun(WebAppServletContext.java:3436)
	at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:3402)
	at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321)
	at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:120)
	at weblogic.servlet.provider.WlsSubjectHandle.run(WlsSubjectHandle.java:57)
	at weblogic.servlet.internal.WebAppServletContext.doSecuredExecute(WebAppServletContext.java:2285)
	at weblogic.servlet.internal.WebAppServletContext.securedExecute(WebAppServletContext.java:2201)
	at weblogic.servlet.internal.WebAppServletContext.execute(WebAppServletContext.java:2179)
	at weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.java:1572)
	at weblogic.servlet.provider.ContainerSupportProviderImpl$WlsRequestExecutor.run(ContainerSupportProviderImpl.java:255)
	at weblogic.work.ExecuteThread.execute(ExecuteThread.java:311)
	at weblogic.work.ExecuteThread.run(ExecuteThread.java:263)