The icecore:refresh component does not support EL expression.

This work:
<icecore:refresh interval="5"/>

This does not work:
<icecore:refresh interval="#{backingBean.refreshInterval}"/>
It produces to following stacktrace:
java.lang.NumberFormatException: For input string: "#{backingBean.refreshInterval}"
at java.lang.NumberFormatException.forInputString(Unknown Source)
at java.lang.Long.parseLong(Unknown Source)
at java.lang.Long.valueOf(Unknown Source)
at org.icefaces.impl.facelets.tag.icefaces.core.RefreshHandler.<init>(RefreshHandler.java:34)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.sun.faces.facelets.tag.AbstractTagLibrary$HandlerFactory.createHandler(AbstractTagLibrary.java:187)
at com.sun.faces.facelets.tag.AbstractTagLibrary.createTagHandler(AbstractTagLibrary.java:678)
at com.sun.faces.facelets.tag.CompositeTagLibrary.createTagHandler(CompositeTagLibrary.java:184)
at com.sun.faces.facelets.compiler.TagUnit.createFaceletHandler(TagUnit.java:120)
at com.sun.faces.facelets.compiler.TextUnit.createFaceletHandler(TextUnit.java:117)
at com.sun.faces.facelets.compiler.CompilationUnit.getNextFaceletHandler(CompilationUnit.java:115)
at com.sun.faces.facelets.compiler.TagUnit.getNextHandler(TagUnit.java:124)
at javax.faces.view.facelets.TagHandler.<init>(TagHandler.java:116)
at com.sun.faces.facelets.tag.TagHandlerImpl.<init>(TagHandlerImpl.java:58)
at com.sun.faces.facelets.tag.jsf.core.ViewHandler.<init>(ViewHandler.java:110)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.sun.faces.facelets.tag.AbstractTagLibrary$HandlerFactory.createHandler(AbstractTagLibrary.java:187)
at com.sun.faces.facelets.tag.AbstractTagLibrary.createTagHandler(AbstractTagLibrary.java:678)
at com.sun.faces.facelets.tag.CompositeTagLibrary.createTagHandler(CompositeTagLibrary.java:184)
at com.sun.faces.facelets.compiler.TagUnit.createFaceletHandler(TagUnit.java:120)
at com.sun.faces.facelets.compiler.TextUnit.createFaceletHandler(TextUnit.java:117)
at com.sun.faces.facelets.compiler.CompilationUnit.getNextFaceletHandler(CompilationUnit.java:115)
at com.sun.faces.facelets.compiler.TagUnit.getNextHandler(TagUnit.java:124)
at javax.faces.view.facelets.TagHandler.<init>(TagHandler.java:116)
at com.sun.faces.facelets.tag.TagHandlerImpl.<init>(TagHandlerImpl.java:58)
at com.sun.faces.facelets.tag.ui.CompositionHandler.<init>(CompositionHandler.java:99)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.sun.faces.facelets.tag.AbstractTagLibrary$HandlerFactory.createHandler(AbstractTagLibrary.java:187)
at com.sun.faces.facelets.tag.AbstractTagLibrary.createTagHandler(AbstractTagLibrary.java:678)
at com.sun.faces.facelets.tag.CompositeTagLibrary.createTagHandler(CompositeTagLibrary.java:184)
at com.sun.faces.facelets.compiler.TagUnit.createFaceletHandler(TagUnit.java:120)
at com.sun.faces.facelets.compiler.CompilationUnit.getNextFaceletHandler(CompilationUnit.java:115)
at com.sun.faces.facelets.compiler.NamespaceUnit.createFaceletHandler(NamespaceUnit.java:82)
at com.sun.faces.facelets.compiler.CompilationManager.createFaceletHandler(CompilationManager.java:373)
at com.sun.faces.facelets.compiler.SAXCompiler.doCompile(SAXCompiler.java:433)
at com.sun.faces.facelets.compiler.SAXCompiler.doCompile(SAXCompiler.java:395)
at com.sun.faces.facelets.compiler.Compiler.compile(Compiler.java:124)
at com.sun.faces.facelets.impl.DefaultFaceletFactory.createFacelet(DefaultFaceletFactory.java:305)
at com.sun.faces.facelets.impl.DefaultFaceletFactory.access$100(DefaultFaceletFactory.java:93)
at com.sun.faces.facelets.impl.DefaultFaceletFactory$1.newInstance(DefaultFaceletFactory.java:160)
at com.sun.faces.facelets.impl.DefaultFaceletFactory$1.newInstance(DefaultFaceletFactory.java:158)
at com.sun.faces.facelets.impl.DefaultFaceletCache$1.newInstance(DefaultFaceletCache.java:83)
at com.sun.faces.facelets.impl.DefaultFaceletCache$1.newInstance(DefaultFaceletCache.java:78)
at com.sun.faces.util.ExpiringConcurrentCache$1.call(ExpiringConcurrentCache.java:99)
at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source)
at java.util.concurrent.FutureTask.run(Unknown Source)
at com.sun.faces.util.ExpiringConcurrentCache.get(ExpiringConcurrentCache.java:114)
at com.sun.faces.facelets.impl.DefaultFaceletCache.getFacelet(DefaultFaceletCache.java:121)
at com.sun.faces.facelets.impl.DefaultFaceletCache.getFacelet(DefaultFaceletCache.java:62)
at com.sun.faces.facelets.impl.DefaultFaceletFactory.getFacelet(DefaultFaceletFactory.java:256)
at com.sun.faces.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:366)
at com.sun.faces.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:346)
at com.sun.faces.facelets.impl.DefaultFaceletContext.includeFacelet(DefaultFaceletContext.java:199)
at com.sun.faces.facelets.tag.ui.IncludeHandler.apply(IncludeHandler.java:147)
at javax.faces.view.facelets.DelegatingMetaTagHandler.applyNextHandler(DelegatingMetaTagHandler.java:137)
at com.sun.faces.facelets.tag.jsf.ComponentTagHandlerDelegateImpl.apply(ComponentTagHandlerDelegateImpl.java:196)
at javax.faces.view.facelets.DelegatingMetaTagHandler.apply(DelegatingMetaTagHandler.java:120)
at javax.faces.view.facelets.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:98)
at javax.faces.view.facelets.DelegatingMetaTagHandler.applyNextHandler(DelegatingMetaTagHandler.java:137)
at com.sun.faces.facelets.tag.jsf.ComponentTagHandlerDelegateImpl.apply(ComponentTagHandlerDelegateImpl.java:196)
at javax.faces.view.facelets.DelegatingMetaTagHandler.apply(DelegatingMetaTagHandler.java:120)
at javax.faces.view.facelets.DelegatingMetaTagHandler.applyNextHandler(DelegatingMetaTagHandler.java:137)
at com.sun.faces.facelets.tag.jsf.ComponentTagHandlerDelegateImpl.apply(ComponentTagHandlerDelegateImpl.java:196)
at javax.faces.view.facelets.DelegatingMetaTagHandler.apply(DelegatingMetaTagHandler.java:120)
at com.sun.faces.facelets.tag.ui.DefineHandler.applyDefinition(DefineHandler.java:107)
at com.sun.faces.facelets.tag.ui.CompositionHandler.apply(CompositionHandler.java:178)
at com.sun.faces.facelets.impl.DefaultFaceletContext$TemplateManager.apply(DefaultFaceletContext.java:395)
at com.sun.faces.facelets.impl.DefaultFaceletContext.includeDefinition(DefaultFaceletContext.java:366)
at com.sun.faces.facelets.tag.ui.InsertHandler.apply(InsertHandler.java:112)
at javax.faces.view.facelets.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:98)
at javax.faces.view.facelets.DelegatingMetaTagHandler.applyNextHandler(DelegatingMetaTagHandler.java:137)
at com.sun.faces.facelets.tag.jsf.ComponentTagHandlerDelegateImpl.apply(ComponentTagHandlerDelegateImpl.java:196)
at javax.faces.view.facelets.DelegatingMetaTagHandler.apply(DelegatingMetaTagHandler.java:120)
at javax.faces.view.facelets.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:98)
at com.sun.faces.facelets.compiler.NamespaceHandler.apply(NamespaceHandler.java:93)
at javax.faces.view.facelets.CompositeFaceletHandler.apply(CompositeFaceletHandler.java:98)
at com.sun.faces.facelets.compiler.EncodingHandler.apply(EncodingHandler.java:86)
at com.sun.faces.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:308)
at com.sun.faces.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:367)
at com.sun.faces.facelets.impl.DefaultFacelet.include(DefaultFacelet.java:346)
at com.sun.faces.facelets.impl.DefaultFaceletContext.includeFacelet(DefaultFaceletContext.java:199)
at com.sun.faces.facelets.tag.ui.CompositionHandler.apply(CompositionHandler.java:155)
at com.sun.faces.facelets.compiler.NamespaceHandler.apply(NamespaceHandler.java:93)
at com.sun.faces.facelets.compiler.EncodingHandler.apply(EncodingHandler.java:86)
at com.sun.faces.facelets.impl.DefaultFacelet.apply(DefaultFacelet.java:152)
at com.sun.faces.application.view.FaceletViewHandlingStrategy.buildView(FaceletViewHandlingStrategy.java:838)
at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:100)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:139)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:594)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at gestionnaireapplications.filter.AuthenticationFilter.doFilter(AuthenticationFilter.java:43)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:224)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:987)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:579)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:307)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$