VelocityViewServlet : Error processing the template

java.lang.NumberFormatException: null
	at java.lang.Integer.parseInt(Integer.java:415)
	at java.lang.Integer.(Integer.java:620)
	at com.icitic.core.tools.ContentTool.getFolderTemplates(ContentTool.java:225)
	at jrockit.reflect.VirtualNativeMethodInvoker.invoke(Ljava.lang.Object;[Ljava.lang.Object;)Ljava.lang.Object;(Unknown Source)
	at java.lang.reflect.Method.invoke(Ljava.lang.Object;[Ljava.lang.Object;I)Ljava.lang.Object;(Unknown Source)
	at org.apache.velocity.util.introspection.UberspectImpl$VelMethodImpl.invoke(UberspectImpl.java:267)
	at org.apache.velocity.runtime.parser.node.ASTMethod.execute(ASTMethod.java:197)
	at org.apache.velocity.runtime.parser.node.ASTReference.execute(ASTReference.java:175)
	at org.apache.velocity.runtime.parser.node.ASTReference.value(ASTReference.java:327)
	at org.apache.velocity.runtime.parser.node.ASTExpression.value(ASTExpression.java:51)
	at org.apache.velocity.runtime.parser.node.ASTSetDirective.render(ASTSetDirective.java:95)
	at org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.java:230)
	at org.apache.velocity.runtime.directive.VelocimacroProxy.render(VelocimacroProxy.java:172)
	at org.apache.velocity.runtime.parser.node.ASTDirective.render(ASTDirective.java:114)
	at org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.java:230)
	at org.apache.velocity.Template.merge(Template.java:256)
	at org.apache.velocity.tools.view.servlet.VelocityLayoutServlet.mergeTemplate(VelocityLayoutServlet.java:219)
	at org.apache.velocity.tools.view.servlet.VelocityViewServlet.doRequest(VelocityViewServlet.java:480)
	at org.apache.velocity.tools.view.servlet.VelocityViewServlet.doGet(VelocityViewServlet.java:436)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:743)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:856)
	at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:225)
	at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:127)
	at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:230)
	at weblogic.servlet.internal.TailFilter.doFilter(TailFilter.java:26)
	at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:42)
	at com.icitic.core.tools.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:68)
	at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:42)
	at weblogic.servlet.internal.RequestDispatcherImpl.invokeServlet(RequestDispatcherImpl.java:492)
	at weblogic.servlet.internal.RequestDispatcherImpl.forward(RequestDispatcherImpl.java:245)
	at com.icitic.wcm.servlet.VsmlServlet.doGet(VsmlServlet.java:34)