VelocityViewServlet : Error processing a template for path '/join_meeting.html'

java.lang.NullPointerException
	at java.util.LinkedList.remove(Unknown Source)
	at java.util.LinkedList.removeLast(Unknown Source)
	at com.elluminate.utility.SoftHashMap.get(SoftHashMap.java:47)
	at com.elluminate.data.helper.MeetingHelper.getMeeting(MeetingHelper.java:166)
	at com.elluminate.adapter.command.GetMeetingCommand.process(GetMeetingCommand.java:34)
	at com.elluminate.adapter.CommandAdapter.process(CommandAdapter.java:82)
	at com.elluminate.service.adapter.ServiceUtilities.waitOnCommand(ServiceUtilities.java:27)
	at com.elluminate.webgui.PageHandlerHelper.waitOnCommand(PageHandlerHelper.java:262)
	at com.elluminate.webgui.PageHandlerHelper.waitOnCommand(PageHandlerHelper.java:256)
	at com.elluminate.webgui.handlers.JoinMeetingHandler.getMeetingView(JoinMeetingHandler.java:208)
	at com.elluminate.webgui.handlers.JoinMeetingHandler.processPage(JoinMeetingHandler.java:50)
	at com.elluminate.webgui.ControllerServlet.handleRequest(ControllerServlet.java:194)
	at org.apache.velocity.tools.view.servlet.VelocityViewServlet.doRequest(VelocityViewServlet.java:545)
	at org.apache.velocity.tools.view.servlet.VelocityViewServlet.doGet(VelocityViewServlet.java:509)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
	at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:849)
	at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
	at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:454)
	at java.lang.Thread.run(Unknown Source)