Error

VelocityViewServlet : Error processing the template

Invocation of method 'get' in class java.util.ArrayList threw exception class java.lang.IndexOutOfBoundsException : Index: 0, Size: 0 
java.lang.IndexOutOfBoundsException: Index: 0, Size: 0
	at java.util.ArrayList.RangeCheck(ArrayList.java:546)
	at java.util.ArrayList.get(ArrayList.java:321)
	at sun.reflect.GeneratedMethodAccessor344.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:585)
	at org.apache.velocity.runtime.parser.node.ASTMethod.execute(ASTMethod.java:260)
	at org.apache.velocity.runtime.parser.node.ASTReference.execute(ASTReference.java:207)
	at org.apache.velocity.runtime.parser.node.ASTReference.value(ASTReference.java:357)
	at org.apache.velocity.runtime.parser.node.ASTSetDirective.render(ASTSetDirective.java:135)
	at org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.java:271)
	at org.apache.velocity.Template.merge(Template.java:296)
	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:690)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:269)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
	at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:691)
	at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:469)
	at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:403)
	at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:301)
	at org.apache.struts.action.RequestProcessor.doForward(RequestProcessor.java:1063)
	at org.apache.struts.tiles.TilesRequestProcessor.doForward(TilesRequestProcessor.java:263)
	at org.apache.struts.action.RequestProcessor.processForwardConfig(RequestProcessor.java:386)
	at org.apache.struts.tiles.TilesRequestProcessor.processForwardConfig(TilesRequestProcessor.java:318)
	at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:229)
	at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1194)
	at org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:414)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:690)
	at com.elasticpath.web.struts.action.ActionServlet.service(ActionServlet.java:33)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:269)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
	at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:691)
	at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:469)
	at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:403)
	at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:301)
	at org.tuckey.web.filters.urlrewrite.RewrittenUrl.doRewrite(RewrittenUrl.java:188)
	at org.tuckey.web.filters.urlrewrite.UrlRewriteFilter.doFilter(UrlRewriteFilter.java:340)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:215)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
	at com.elasticpath.commons.filter.SeoContextFilter.doFilter(SeoContextFilter.java:62)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:215)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
	at com.elasticpath.commons.EncodingFilter.doFilter(EncodingFilter.java:51)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:215)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
	at com.elasticpath.commons.filter.UnknownCustomerFilter.doFilter(UnknownCustomerFilter.java:85)