NPE when calling operations on inactive modcluster subsystem

Despite not being able to 'see' the modcluster subsystem as illustrated below:
[domain@localhost:9999 subsystem] pwd
/host=master/server=server-one/subsystem
[domain@localhost:9999 subsystem] ls
cmp datasources ee ejb3
infinispan jacorb jaxrs jca
jdr jmx jpa logging
mail messaging naming osgi
remoting resource-adapters sar security
threads transactions web webservices
weld

I can still call methods on that subsystem. However when I do this, there is a NullPointerException thrown by the operation code.

[domain@localhost:9999 /] /host=master/server=server-one/subsystem=modcluster/:read-proxies-configuration
{
"outcome" => "failed",
"result" => undefined,
"failure-description" => "JBAS014749: Operation handler failed: null",
"rolled-back" => true
}

And the log/stacktrace is:

[Server:server-one] 11:39:45,518 ERROR [org.jboss.as.controller.management-operation] (pool-1-thread-3) JBAS014612: Operation ("read-proxies-configuration") failed - address: ([("subsystem" => "modcluster")]): java.lang.NullPointerException
[Server:server-one] at org.jboss.as.modcluster.ModClusterGetProxyConfiguration$1.execute(ModClusterGetProxyConfiguration.java:56) [jboss-as-modcluster-7.1.0.CR1-SNAPSHOT.jar:]
[Server:server-one] at org.jboss.as.controller.AbstractOperationContext.executeStep(AbstractOperationContext.java:359) [jboss-as-controller-7.1.0.CR1-SNAPSHOT.jar:]
[Server:server-one] at org.jboss.as.controller.AbstractOperationContext.doCompleteStep(AbstractOperationContext.java:254) [jboss-as-controller-7.1.0.CR1-SNAPSHOT.jar:]
[Server:server-one] at org.jboss.as.controller.AbstractOperationContext.completeStep(AbstractOperationContext.java:190) [jboss-as-controller-7.1.0.CR1-SNAPSHOT.jar:]
[Server:server-one] at org.jboss.as.modcluster.ModClusterGetProxyConfiguration.execute(ModClusterGetProxyConfiguration.java:75) [jboss-as-modcluster-7.1.0.CR1-SNAPSHOT.jar:]
[Server:server-one] at org.jboss.as.controller.AbstractOperationContext.executeStep(AbstractOperationContext.java:359) [jboss-as-controller-7.1.0.CR1-SNAPSHOT.jar:]
[Server:server-one] at org.jboss.as.controller.AbstractOperationContext.doCompleteStep(AbstractOperationContext.java:254) [jboss-as-controller-7.1.0.CR1-SNAPSHOT.jar:]
[Server:server-one] at org.jboss.as.controller.AbstractOperationContext.completeStep(AbstractOperationContext.java:190) [jboss-as-controller-7.1.0.CR1-SNAPSHOT.jar:]
[Server:server-one] at org.jboss.as.controller.ModelControllerImpl$DefaultPrepareStepHandler.execute(ModelControllerImpl.java:432) [jboss-as-controller-7.1.0.CR1-SNAPSHOT.jar:]
[Server:server-one] at org.jboss.as.controller.AbstractOperationContext.executeStep(AbstractOperationContext.java:359) [jboss-as-controller-7.1.0.CR1-SNAPSHOT.jar:]
[Server:server-one] at org.jboss.as.controller.AbstractOperationContext.doCompleteStep(AbstractOperationContext.java:254) [jboss-as-controller-7.1.0.CR1-SNAPSHOT.jar:]
[Server:server-one] at org.jboss.as.controller.AbstractOperationContext.completeStep(AbstractOperationContext.java:190) [jboss-as-controller-7.1.0.CR1-SNAPSHOT.jar:]
[Server:server-one] at org.jboss.as.controller.ModelControllerImpl.execute(ModelControllerImpl.java:119) [jboss-as-controller-7.1.0.CR1-SNAPSHOT.jar:]
[Server:server-one] at org.jboss.as.controller.remote.TransactionalModelControllerOperationHandler$ExecuteRequestHandler.doExecute(TransactionalModelControllerOperationHandler.java:142) [jboss-as-controller-7.1.0.CR1-SNAPSHOT.jar:]
[Server:server-one] at org.jboss.as.controller.remote.TransactionalModelControllerOperationHandler$ExecuteRequestHandler$1.execute(TransactionalModelControllerOperationHandler.java:128) [jboss-as-controller-7.1.0.CR1-SNAPSHOT.jar:]
[Server:server-one] at org.jboss.as.protocol.mgmt.AbstractMessageHandler$3$1.doExecute(AbstractMessageHandler.java:268)
[Server:server-one] at org.jboss.as.protocol.mgmt.AbstractMessageHandler$AsyncTaskRunner.run(AbstractMessageHandler.java:424)
[Server:server-one] at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) [:1.6.0_29]
[Server:server-one] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) [:1.6.0_29]
[Server:server-one] at java.lang.Thread.run(Thread.java:680) [:1.6.0_29]
[Server:server-one]