NullPointerException when Export Metadata

[IPST LIbrary]

Dspace was built from latest git source. When click Export Metadata from menu, I got this error

org.apache.cocoon.ProcessingException: Failed to process reader
	at <map:read type="MetadataExportReader"> - jndi:/localhost/sitemap.xmap:387:71
	at <map:match> - jndi:/localhost/sitemap.xmap:386:61
	at org.apache.cocoon.ProcessingException.throwLocated(ProcessingException.java:111)
	at org.apache.cocoon.components.pipeline.AbstractProcessingPipeline.handleException(AbstractProcessingPipeline.java:927)
	at org.apache.cocoon.components.pipeline.AbstractProcessingPipeline.setupReader(AbstractProcessingPipeline.java:568)
	at org.apache.cocoon.components.pipeline.AbstractProcessingPipeline.preparePipeline(AbstractProcessingPipeline.java:464)
	at org.apache.cocoon.components.pipeline.AbstractProcessingPipeline.process(AbstractProcessingPipeline.java:411)
	at sun.reflect.GeneratedMethodAccessor124.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:497)
	at org.apache.cocoon.core.container.spring.avalon.PoolableProxyHandler.invoke(PoolableProxyHandler.java:71)
	at com.sun.proxy.$Proxy94.process(Unknown Source)
	at org.apache.cocoon.components.treeprocessor.sitemap.ReadNode.invoke(ReadNode.java:94)
	at org.apache.cocoon.components.treeprocessor.AbstractParentProcessingNode.invokeNodes(AbstractParentProcessingNode.java:55)
	at org.apache.cocoon.components.treeprocessor.sitemap.MatchNode.invoke(MatchNode.java:87)
	at org.apache.cocoon.components.treeprocessor.AbstractParentProcessingNode.invokeNodes(AbstractParentProcessingNode.java:78)
	at org.apache.cocoon.components.treeprocessor.sitemap.PipelineNode.invoke(PipelineNode.java:143)
	at org.apache.cocoon.components.treeprocessor.AbstractParentProcessingNode.invokeNodes(AbstractParentProcessingNode.java:78)
	at org.apache.cocoon.components.treeprocessor.sitemap.PipelinesNode.invoke(PipelinesNode.java:81)
	at org.apache.cocoon.components.treeprocessor.ConcreteTreeProcessor.process(ConcreteTreeProcessor.java:239)
	at org.apache.cocoon.components.treeprocessor.ConcreteTreeProcessor.process(ConcreteTreeProcessor.java:171)
	at org.apache.cocoon.components.treeprocessor.TreeProcessor.process(TreeProcessor.java:247)
	at org.apache.cocoon.servlet.RequestProcessor.process(RequestProcessor.java:351)
	at org.apache.cocoon.servlet.RequestProcessor.service(RequestProcessor.java:169)
	at org.apache.cocoon.sitemap.SitemapServlet.service(SitemapServlet.java:84)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
	at org.apache.cocoon.servletservice.ServletServiceContext$PathDispatcher.forward(ServletServiceContext.java:468)
	at org.apache.cocoon.servletservice.ServletServiceContext$PathDispatcher.forward(ServletServiceContext.java:443)
	at org.apache.cocoon.servletservice.spring.ServletFactoryBean$ServiceInterceptor.invoke(ServletFactoryBean.java:264)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
	at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204)
	at com.sun.proxy.$Proxy91.service(Unknown Source)
	at org.dspace.springmvc.CocoonView.render(CocoonView.java:113)
	at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1216)
	at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1001)
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:945)
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:867)
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:953)
	at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:844)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:620)
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:829)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
	at org.dspace.app.xmlui.cocoon.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:111)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
	at org.dspace.app.xmlui.cocoon.DSpaceCocoonServletFilter.doFilter(DSpaceCocoonServletFilter.java:277)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
	at org.dspace.app.xmlui.cocoon.servlet.multipart.DSpaceMultipartFilter.doFilter(DSpaceMultipartFilter.java:119)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
	at org.dspace.utils.servlet.DSpaceWebappServletFilter.doFilter(DSpaceWebappServletFilter.java:78)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
	at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
	at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1041)
	at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:607)
	at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:313)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NullPointerException
	at org.dspace.app.bulkedit.MetadataExport.buildFromCommunity(MetadataExport.java:104)
	at org.dspace.app.bulkedit.MetadataExport.<init>(MetadataExport.java:70)
	at org.dspace.app.xmlui.cocoon.MetadataExportReader.setup(MetadataExportReader.java:141)
	at sun.reflect.GeneratedMethodAccessor57.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:497)
	at org.apache.cocoon.core.container.spring.avalon.PoolableProxyHandler.invoke(PoolableProxyHandler.java:71)
	at com.sun.proxy.$Proxy95.setup(Unknown Source)
	at org.apache.cocoon.components.pipeline.AbstractProcessingPipeline.setupReader(AbstractProcessingPipeline.java:560)
	... 65 more