VelocityViewServlet : Error processing the template

Invocation of method 'get' in class java.util.TreeMap threw exception class java.lang.NullPointerException : null
java.lang.NullPointerException
	at java.util.TreeMap.getEntry(TreeMap.java:358)
	at java.util.TreeMap.get(TreeMap.java:289)
	at sun.reflect.GeneratedMethodAccessor123.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:55)
	at java.lang.reflect.Method.invoke(Method.java:508)
	at org.apache.velocity.util.introspection.UberspectImpl$VelMethodImpl.invoke(UberspectImpl.java:267)
	at org.apache.velocity.runtime.parser.node.ASTMethod.execute(ASTMethod.java:197)
	at org.apache.velocity.runtime.parser.node.ASTReference.execute(ASTReference.java:175)
	at org.apache.velocity.runtime.parser.node.ASTReference.value(ASTReference.java:327)
	at org.apache.velocity.runtime.parser.node.ASTExpression.value(ASTExpression.java:51)
	at org.apache.velocity.runtime.parser.node.ASTSetDirective.render(ASTSetDirective.java:95)
	at org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.java:230)
	at org.apache.velocity.runtime.directive.VelocimacroProxy.render(VelocimacroProxy.java:172)
	at org.apache.velocity.runtime.parser.node.ASTDirective.render(ASTDirective.java:114)
	at org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.java:230)
	at org.apache.velocity.Template.merge(Template.java:256)
	at org.apache.velocity.tools.view.servlet.VelocityViewServlet.mergeTemplate(VelocityViewServlet.java:592)
	at org.apache.velocity.tools.view.servlet.VelocityViewServlet.doRequest(VelocityViewServlet.java:417)
	at org.apache.velocity.tools.view.servlet.VelocityViewServlet.doGet(VelocityViewServlet.java:373)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:575)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:668)
	at com.ibm.ws.webcontainer.servlet.ServletWrapper.service(ServletWrapper.java:1232)
	at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:781)
	at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:480)
	at com.ibm.ws.webcontainer.servlet.ServletWrapperImpl.handleRequest(ServletWrapperImpl.java:178)
	at com.ibm.ws.webcontainer.filter.WebAppFilterChain.invokeTarget(WebAppFilterChain.java:136)
	at com.ibm.ws.webcontainer.filter.WebAppFilterChain.doFilter(WebAppFilterChain.java:79)
	at com.ibm.ws.webcontainer.filter.WebAppFilterManager.doFilter(WebAppFilterManager.java:967)
	at com.ibm.ws.webcontainer.filter.WebAppFilterManager.invokeFilters(WebAppFilterManager.java:1107)
	at com.ibm.ws.webcontainer.webapp.WebAppRequestDispatcher.dispatch(WebAppRequestDispatcher.java:1385)
	at com.ibm.ws.webcontainer.webapp.WebAppRequestDispatcher.forward(WebAppRequestDispatcher.java:194)
	at org.apache.struts.action.RequestProcessor.doForward(RequestProcessor.java:1069)
	at org.apache.struts.action.RequestProcessor.processForwardConfig(RequestProcessor.java:455)
	at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:279)
	at net.kasite.event.core.http.RentRequestProcessor.process(RentRequestProcessor.java:64)
	at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1482)
	at org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:507)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:575)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:668)
	at com.ibm.ws.webcontainer.servlet.ServletWrapper.service(ServletWrapper.java:1232)
	at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:781)
	at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:480)
	at com.ibm.ws.webcontainer.servlet.ServletWrapperImpl.handleRequest(ServletWrapperImpl.java:178)
	at com.ibm.ws.webcontainer.filter.WebAppFilterChain.invokeTarget(WebAppFilterChain.java:136)
	at com.ibm.ws.webcontainer.filter.WebAppFilterChain.doFilter(WebAppFilterChain.java:79)
	at com.ibm.ws.webcontainer.filter.WebAppFilterManager.doFilter(WebAppFilterManager.java:967)
	at com.ibm.ws.webcontainer.filter.WebAppFilterManager.invokeFilters(WebAppFilterManager.java:1107)
	at com.ibm.ws.webcontainer.webapp.WebAppRequestDispatcher.dispatch(WebAppRequestDispatcher.java:1385)
	at com.ibm.ws.webcontainer.webapp.WebAppRequestDispatcher.forward(WebAppRequestDispatcher.java:194)
	at org.apache.struts.action.RequestProcessor.doForward(RequestProcessor.java:1069)
	at org.apache.struts.action.RequestProcessor.processForwardConfig(RequestProcessor.java:455)
	at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:279)
	at net.kasite.event.core.http.RentRequestProcessor.process(RentRequestProcessor.java:64)
	at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1482)
	at org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:507)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:575)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:668)
	at com.ibm.ws.webcontainer.servlet.ServletWrapper.service(ServletWrapper.java:1232)
	at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:781)
	at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:480)
	at com.ibm.ws.webcontainer.servlet.ServletWrapperImpl.handleRequest(ServletWrapperImpl.java:178)
	at com.ibm.ws.webcontainer.filter.WebAppFilterChain.invokeTarget(WebAppFilterChain.java:136)
	at com.ibm.ws.webcontainer.filter.WebAppFilterChain.doFilter(WebAppFilterChain.java:97)
	at net.kasite.event.core.filters.GetHttpRequestFilter.doFilter(GetHttpRequestFilter.java:43)
	at com.ibm.ws.webcontainer.filter.FilterInstanceWrapper.doFilter(FilterInstanceWrapper.java:195)
	at com.ibm.ws.webcontainer.filter.WebAppFilterChain.doFilter(WebAppFilterChain.java:91)
	at net.kasite.event.core.filters.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:184)
	at com.ibm.ws.webcontainer.filter.FilterInstanceWrapper.doFilter(FilterInstanceWrapper.java:195)
	at com.ibm.ws.webcontainer.filter.WebAppFilterChain.doFilter(WebAppFilterChain.java:91)
	at com.ibm.ws.webcontainer.filter.WebAppFilterManager.doFilter(WebAppFilterManager.java:967)
	at com.ibm.ws.webcontainer.filter.WebAppFilterManager.invokeFilters(WebAppFilterManager.java:1107)
	at com.ibm.ws.webcontainer.servlet.CacheServletWrapper.handleRequest(CacheServletWrapper.java:87)
	at com.ibm.ws.webcontainer.WebContainer.handleRequest(WebContainer.java:947)
	at com.ibm.ws.webcontainer.WSWebContainer.handleRequest(WSWebContainer.java:1817)
	at com.ibm.ws.webcontainer.channel.WCChannelLink.ready(WCChannelLink.java:200)
	at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.handleDiscrimination(HttpInboundLink.java:463)
	at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.handleNewRequest(HttpInboundLink.java:530)
	at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.processRequest(HttpInboundLink.java:316)
	at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.ready(HttpInboundLink.java:287)
	at com.ibm.ws.ssl.channel.impl.SSLConnectionLink.determineNextChannel(SSLConnectionLink.java:1084)
	at com.ibm.ws.ssl.channel.impl.SSLConnectionLink.readyInboundPostHandshake(SSLConnectionLink.java:732)
	at com.ibm.ws.ssl.channel.impl.SSLConnectionLink$MyHandshakeCompletedCallback.complete(SSLConnectionLink.java:428)
	at com.ibm.ws.ssl.channel.impl.SSLUtils.handleHandshake(SSLUtils.java:1138)
	at com.ibm.ws.ssl.channel.impl.SSLHandshakeIOCallback.complete(SSLHandshakeIOCallback.java:87)
	at com.ibm.ws.tcp.channel.impl.AioReadCompletionListener.futureCompleted(AioReadCompletionListener.java:175)
	at com.ibm.io.async.AbstractAsyncFuture.invokeCallback(AbstractAsyncFuture.java:217)
	at com.ibm.io.async.AsyncChannelFuture.fireCompletionActions(AsyncChannelFuture.java:161)
	at com.ibm.io.async.AsyncFuture.completed(AsyncFuture.java:138)
	at com.ibm.io.async.ResultHandler.complete(ResultHandler.java:204)
	at com.ibm.io.async.ResultHandler.runEventProcessingLoop(ResultHandler.java:775)
	at com.ibm.io.async.ResultHandler$2.run(ResultHandler.java:905)
	at com.ibm.ws.util.ThreadPool$Worker.run(ThreadPool.java:1892)