VelocityServlet : Error processing the template

org.apache.velocity.exception.MethodInvocationException: Invocation of method 'elementAt' in  class java.util.Vector threw exception class java.lang.ArrayIndexOutOfBoundsException : 0 >= 0
org.apache.velocity.exception.MethodInvocationException: Invocation of method 'elementAt' in  class java.util.Vector threw exception class java.lang.ArrayIndexOutOfBoundsException : 0 >= 0
	at org.apache.velocity.runtime.parser.node.ASTMethod.execute(ASTMethod.java:309)
	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.servlet.VelocityServlet.mergeTemplate(VelocityServlet.java:448)
	at org.apache.velocity.servlet.VelocityServlet.doRequest(VelocityServlet.java:387)
	at org.apache.velocity.servlet.VelocityServlet.doGet(VelocityServlet.java:333)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:115)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:92)
	at com.caucho.server.dispatch.ServletFilterChain.doFilter(ServletFilterChain.java:106)
	at com.caucho.server.webapp.WebAppFilterChain.doFilter(WebAppFilterChain.java:178)
	at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229)
	at com.caucho.server.http.HttpRequest.handleRequest(HttpRequest.java:268)
	at com.caucho.server.port.TcpConnection.run(TcpConnection.java:389)
	at com.caucho.util.ThreadPool.runTasks(ThreadPool.java:507)
	at com.caucho.util.ThreadPool.run(ThreadPool.java:433)
	at java.lang.Thread.run(Thread.java:534)