Using mod_cluster custom mbean metric class intermittently fails with "NoClassDefFoundError: javax/management/MalformedObjectNameException"

        <subsystem xmlns="urn:jboss:domain:modcluster:2.0">
            <mod-cluster-config advertise-socket="modcluster" proxies="proxy1" connector="ajp">
                <dynamic-load-provider>
                    <custom-load-metric class="org.jboss.modcluster.load.metric.impl.MBeanAttributeLoadMetric" capacity="5.0">
                        <property name="pattern" value="com.acme.metrics:service=InitialDownloadResult"/>
                        <property name="attribute" value="CurrentRequestCount"/>
                    </custom-load-metric>
                </dynamic-load-provider>
            </mod-cluster-config>
        </subsystem>

19:40:03,880 ERROR [org.jboss.as.controller.management-operation] (ServerService Thread Pool -- 50) WFLYCTL0013: Operation ("add") failed - address: ([("subsystem" => "modcluster")]): java.lang.NoClassDefFoundError: javax/management/MalformedObjectNameException
	at java.lang.Class.forName0(Native Method)
	at java.lang.Class.forName(Class.java:264)
	at org.jboss.common.beans.property.BeanUtils.findClass(BeanUtils.java:146)
	at org.jboss.common.beans.property.finder.DefaultPropertyEditorFinder.find(DefaultPropertyEditorFinder.java:185)
	at org.jboss.common.beans.property.BeanUtils.mapJavaBeanProperties(BeanUtils.java:308)
	at org.wildfly.extension.mod_cluster.ModClusterSubsystemAdd.addLoadMetrics(ModClusterSubsystemAdd.java:354)
	at org.wildfly.extension.mod_cluster.ModClusterSubsystemAdd.getModClusterLoadProvider(ModClusterSubsystemAdd.java:294)
	at org.wildfly.extension.mod_cluster.ModClusterSubsystemAdd.performBoottime(ModClusterSubsystemAdd.java:124)
	at org.jboss.as.controller.AbstractBoottimeAddStepHandler.performBoottime(AbstractBoottimeAddStepHandler.java:157)
	at org.jboss.as.controller.AbstractBoottimeAddStepHandler.performRuntime(AbstractBoottimeAddStepHandler.java:116)
	at org.jboss.as.controller.AbstractAddStepHandler$1.execute(AbstractAddStepHandler.java:151)
	at org.jboss.as.controller.AbstractOperationContext.executeStep(AbstractOperationContext.java:890)
	at org.jboss.as.controller.AbstractOperationContext.processStages(AbstractOperationContext.java:659)
	at org.jboss.as.controller.AbstractOperationContext.executeOperation(AbstractOperationContext.java:370)
	at org.jboss.as.controller.ParallelBootOperationStepHandler$ParallelBootTask.run(ParallelBootOperationStepHandler.java:359)
	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)
	at org.jboss.threads.JBossThread.run(JBossThread.java:320)
Caused by: java.lang.ClassNotFoundException: javax.management.MalformedObjectNameException from [Module "org.jboss.common-beans:main" from local module loader @6956de9 (finder: local module finder @769c9116 (roots: /Users/rhusar/STATIC/wf10/load/wildfly-10.0.0.Final/modules,/Users/rhusar/STATIC/wf10/load/wildfly-10.0.0.Final/modules/system/layers/base))]
	at org.jboss.modules.ModuleClassLoader.findClass(ModuleClassLoader.java:198)
	at org.jboss.modules.ConcurrentClassLoader.performLoadClassUnchecked(ConcurrentClassLoader.java:363)
	at org.jboss.modules.ConcurrentClassLoader.performLoadClass(ConcurrentClassLoader.java:351)
	at org.jboss.modules.ConcurrentClassLoader.loadClass(ConcurrentClassLoader.java:93)
	... 19 more