java.lang.StringIndexOutOfBoundsException: String index out of range: 0
	at java.lang.String.charAt(String.java:658) ~[na:1.7.0_80]
	at org.zkoss.bind.proxy.BeanProxyHandler.toAttrName(BeanProxyHandler.java:243) ~[zkbind-8.0.3.jar:8.0.3]
	at org.zkoss.bind.proxy.BeanProxyHandler.toAttrName(BeanProxyHandler.java:248) ~[zkbind-8.0.3.jar:8.0.3]
	at org.zkoss.bind.proxy.BeanProxyHandler.invoke(BeanProxyHandler.java:181) ~[zkbind-8.0.3.jar:8.0.3]
	at org.zkoss.bind.proxy.FormProxyHandler.invoke(FormProxyHandler.java:191) ~[zkbind-8.0.3.jar:8.0.3]
	at org.springframework.util.LinkedCaseInsensitiveMap_$$_jvst90b_0.get(LinkedCaseInsensitiveMap_$$_jvst90b_0.java) ~[spring-core-4.3.2.RELEASE.jar:4.3.2.RELEASE]
	at org.zkoss.zel.MapELResolver.getValue(MapELResolver.java:66) ~[zel-8.0.3.jar:8.0.3]
	at org.zkoss.zel.CompositeELResolver.getValue(CompositeELResolver.java:66) ~[zel-8.0.3.jar:8.0.3]
	at org.zkoss.zel.CompositeELResolver.getValue(CompositeELResolver.java:66) ~[zel-8.0.3.jar:8.0.3]
	at org.zkoss.xel.zel.XelELResolver.getValue(XelELResolver.java:99) ~[zcommon-8.0.3.jar:8.0.3]
	at org.zkoss.bind.xel.zel.BindELResolver.getValue(BindELResolver.java:121) ~[zkbind-8.0.3.jar:8.0.3]
	at org.zkoss.zel.impl.parser.AstValue.getValue(AstValue.java:188) ~[zel-8.0.3.jar:8.0.3]
	at org.zkoss.zel.impl.ValueExpressionImpl.getValue(ValueExpressionImpl.java:184) ~[zel-8.0.3.jar:8.0.3]
	at org.zkoss.xel.zel.ELXelExpression.evaluate(ELXelExpression.java:41) ~[zcommon-8.0.3.jar:8.0.3]
	at org.zkoss.bind.impl.BindEvaluatorXImpl.getValue(BindEvaluatorXImpl.java:46) ~[zkbind-8.0.3.jar:8.0.3]
	at org.zkoss.bind.impl.LoadPropertyBindingImpl.load(LoadPropertyBindingImpl.java:58) ~[zkbind-8.0.3.jar:8.0.3]
	at org.zkoss.bind.impl.BinderImpl.doPropertyChange0(BinderImpl.java:452) ~[zkbind-8.0.3.jar:8.0.3]
	at org.zkoss.bind.impl.BinderImpl.doPropertyChange(BinderImpl.java:427) ~[zkbind-8.0.3.jar:8.0.3]
	at org.zkoss.bind.impl.BinderImpl.access$300(BinderImpl.java:129) ~[zkbind-8.0.3.jar:8.0.3]
	at org.zkoss.bind.impl.BinderImpl$QueueListener.onEvent(BinderImpl.java:386) ~[zkbind-8.0.3.jar:8.0.3]
	at org.zkoss.zk.ui.event.impl.DesktopEventQueue$QueueListener.onEvent(DesktopEventQueue.java:168) ~[zk-8.0.3.jar:8.0.3]
	at org.zkoss.zk.ui.AbstractComponent.onEvent(AbstractComponent.java:3163) ~[zk-8.0.3.jar:8.0.3]
	at org.zkoss.zk.ui.AbstractComponent.service(AbstractComponent.java:3133) ~[zk-8.0.3.jar:8.0.3]
	at org.zkoss.zk.ui.AbstractComponent.service(AbstractComponent.java:3075) ~[zk-8.0.3.jar:8.0.3]
	at org.zkoss.zk.ui.impl.EventProcessor.process(EventProcessor.java:138) ~[zk-8.0.3.jar:8.0.3]
	at org.zkoss.zk.ui.impl.UiEngineImpl.processEvent(UiEngineImpl.java:1853) [zk-8.0.3.jar:8.0.3]
	at org.zkoss.zk.ui.impl.UiEngineImpl.process(UiEngineImpl.java:1625) [zk-8.0.3.jar:8.0.3]
	at org.zkoss.zk.ui.impl.UiEngineImpl.execNewPage0(UiEngineImpl.java:548) [zk-8.0.3.jar:8.0.3]
	at org.zkoss.zk.ui.impl.UiEngineImpl.execNewPage(UiEngineImpl.java:369) [zk-8.0.3.jar:8.0.3]
	at org.zkoss.zk.ui.http.DHtmlLayoutServlet.process(DHtmlLayoutServlet.java:211) [zk-8.0.3.jar:8.0.3]
	at org.zkoss.zk.ui.http.DHtmlLayoutServlet.doGet(DHtmlLayoutServlet.java:137) [zk-8.0.3.jar:8.0.3]
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:624) [tomcat-embed-core-7.0.70.jar:7.0.70]
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:731) [tomcat-embed-core-7.0.70.jar:7.0.70]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303) [tomcat-embed-core-7.0.70.jar:7.0.70]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) [tomcat-embed-core-7.0.70.jar:7.0.70]
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) [tomcat-embed-websocket-7.0.70.jar:7.0.70]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) [tomcat-embed-core-7.0.70.jar:7.0.70]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) [tomcat-embed-core-7.0.70.jar:7.0.70]
	at org.springframework.boot.web.filter.ApplicationContextHeaderFilter.doFilterInternal(ApplicationContextHeaderFilter.java:55) [spring-boot-1.4.0.RELEASE.jar:1.4.0.RELEASE]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.3.2.RELEASE.jar:4.3.2.RELEASE]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) [tomcat-embed-core-7.0.70.jar:7.0.70]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) [tomcat-embed-core-7.0.70.jar:7.0.70]
	at org.springframework.boot.actuate.trace.WebRequestTraceFilter.doFilterInternal(WebRequestTraceFilter.java:105) [spring-boot-actuator-1.4.0.RELEASE.jar:1.4.0.RELEASE]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.3.2.RELEASE.jar:4.3.2.RELEASE]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) [tomcat-embed-core-7.0.70.jar:7.0.70]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) [tomcat-embed-core-7.0.70.jar:7.0.70]
	at org.grails.web.servlet.mvc.GrailsWebRequestFilter.doFilterInternal(GrailsWebRequestFilter.java:77) [grails-web-mvc-3.2.0.jar:3.2.0]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.3.2.RELEASE.jar:4.3.2.RELEASE]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) [tomcat-embed-core-7.0.70.jar:7.0.70]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) [tomcat-embed-core-7.0.70.jar:7.0.70]
	at org.grails.web.filters.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:67) [grails-web-mvc-3.2.0.jar:3.2.0]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.3.2.RELEASE.jar:4.3.2.RELEASE]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) [tomcat-embed-core-7.0.70.jar:7.0.70]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) [tomcat-embed-core-7.0.70.jar:7.0.70]
	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197) [spring-web-4.3.2.RELEASE.jar:4.3.2.RELEASE]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.3.2.RELEASE.jar:4.3.2.RELEASE]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) [tomcat-embed-core-7.0.70.jar:7.0.70]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) [tomcat-embed-core-7.0.70.jar:7.0.70]
	at org.springframework.boot.actuate.autoconfigure.MetricsFilter.doFilterInternal(MetricsFilter.java:107) [spring-boot-actuator-1.4.0.RELEASE.jar:1.4.0.RELEASE]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.3.2.RELEASE.jar:4.3.2.RELEASE]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) [tomcat-embed-core-7.0.70.jar:7.0.70]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) [tomcat-embed-core-7.0.70.jar:7.0.70]
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:218) [tomcat-embed-core-7.0.70.jar:7.0.70]
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122) [tomcat-embed-core-7.0.70.jar:7.0.70]
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505) [tomcat-embed-core-7.0.70.jar:7.0.70]
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169) [tomcat-embed-core-7.0.70.jar:7.0.70]
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103) [tomcat-embed-core-7.0.70.jar:7.0.70]
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116) [tomcat-embed-core-7.0.70.jar:7.0.70]
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:442) [tomcat-embed-core-7.0.70.jar:7.0.70]
	at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1082) [tomcat-embed-core-7.0.70.jar:7.0.70]
	at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:623) [tomcat-embed-core-7.0.70.jar:7.0.70]
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1756) [tomcat-embed-core-7.0.70.jar:7.0.70]
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1715) [tomcat-embed-core-7.0.70.jar:7.0.70]
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) [na:1.7.0_80]
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) [na:1.7.0_80]
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-7.0.70.jar:7.0.70]
	at java.lang.Thread.run(Thread.java:745) [na:1.7.0_80]