I have developped my own subsytem and I start using :read-resource for example on my module. That work ok. Then I used :read-children-names on my subsystem which failed with:

14:03:58,330 INFO [com.xxx.dns.DnsAlarm] (pool-7-thread-1) DnsAlarm: clear DnsUnreachableAlarm
14:13:53,166 ERROR [org.jboss.as.controller] (pool-2-thread-9) Operation ("read-children-names") failed - address: ([("subsystem" => "xxx")]) - failure description: "child-type may not be null."

Then I went into the osgi subsytem and run the same command. Got the same type of error:

14:14:39,463 ERROR [org.jboss.as.controller] (pool-2-thread-16) Operation ("read-children-names") failed - address: ([("subsystem" => "osgi")]) - failure description: "child-type may not be null."

BUT, I also got :
14:14:49,623 WARN [org.jboss.as.protocol] (pool-2-thread-11) Got error closing channel JBREM00206: Channel is not open

And from this point on the jboss-admin.sh is no longer able to do a :read-resource

I do not see why the communication link would become broken since I did not disconnect the jboss-admin.

Not only that, if I reconnect back to the AS 7 I can no longer run the :read-resource on my subsystem, but then I can use it on the osgi until I create the same error. Once I do that I can go back into my subsystem and run the :read-resource again.

So, kind of lost due to this unpredictability .....

14:14:39,463 ERROR [org.jboss.as.controller] (pool-2-thread-16) Operation ("read-children-names") failed - address: ([("subsystem" => "osgi")]) - failure description: "child-type may not be null."
14:14:49,623 WARN [org.jboss.as.protocol] (pool-2-thread-11) Got error closing channel JBREM00206: Channel is not open
14:23:28,037 ERROR [org.jboss.as.controller] (pool-2-thread-20) Operation ("read-children-names") failed - address: ([("subsystem" => "osgi")]) - failure description: "child-type may not be null."
14:23:30,515 ERROR [org.jboss.as.controller] (pool-2-thread-17) Operation ("read-children-names") failed - address: ([("subsystem" => "osgi")]) - failure description: "child-type may not be null."
14:23:32,349 ERROR [org.jboss.as.controller] (pool-2-thread-19) Operation ("read-children-names") failed - address: ([("subsystem" => "osgi")]) - failure description: "child-type may not be null."
14:23:47,093 ERROR [org.jboss.as.controller] (pool-2-thread-17) Operation ("read-children-resources") failed - address: ([("subsystem" => "osgi")]) - failure description: "child-type may not be null."
14:23:49,113 ERROR [org.jboss.as.controller] (pool-2-thread-17) Operation ("read-children-resources") failed - address: ([("subsystem" => "osgi")]) - failure description: "child-type may not be null."
14:23:50,123 ERROR [org.jboss.as.controller] (pool-2-thread-23) Operation ("read-children-resources") failed - address: ([("subsystem" => "osgi")]) - failure description: "child-type may not be null."
14:23:50,481 ERROR [org.jboss.as.controller] (pool-2-thread-24) Operation ("read-children-resources") failed - address: ([("subsystem" => "osgi")]) - failure description: "child-type may not be null."
14:23:50,721 ERROR [org.jboss.as.controller] (pool-2-thread-20) Operation ("read-children-resources") failed - address: ([("subsystem" => "osgi")]) - failure description: "child-type may not be null."
14:23:50,954 ERROR [org.jboss.as.controller] (pool-2-thread-17) Operation ("read-children-resources") failed - address: ([("subsystem" => "osgi")]) - failure description: "child-type may not be null."
14:23:51,166 ERROR [org.jboss.as.controller] (pool-2-thread-20) Operation ("read-children-resources") failed - address: ([("subsystem" => "osgi")]) - failure description: "child-type may not be null."
14:23:51,374 ERROR [org.jboss.as.controller] (pool-2-thread-19) Operation ("read-children-resources") failed - address: ([("subsystem" => "osgi")]) - failure description: "child-type may not be null."
14:23:51,605 ERROR [org.jboss.as.controller] (pool-2-thread-19) Operation ("read-children-resources") failed - address: ([("subsystem" => "osgi")]) - failure description: "child-type may not be null."
14:23:51,813 ERROR [org.jboss.as.controller] (pool-2-thread-23) Operation ("read-children-resources") failed - address: ([("subsystem" => "osgi")]) - failure description: "child-type may not be null."
14:23:52,034 ERROR [org.jboss.as.controller] (pool-2-thread-19) Operation ("read-children-resources") failed - address: ([("subsystem" => "osgi")]) - failure description: "child-type may not be null."
14:23:52,298 ERROR [org.jboss.as.controller] (pool-2-thread-19) Operation ("read-children-resources") failed - address: ([("subsystem" => "osgi")]) - failure description: "child-type may not be null."
14:23:52,300 WARN [org.jboss.as.protocol] (pool-2-thread-24) Got error closing channel JBREM00206: Channel is not open
14:23:52,489 ERROR [org.jboss.as.controller] (pool-2-thread-24) Operation ("read-children-resources") failed - address: ([("subsystem" => "osgi")]) - failure description: "child-type may not be null."
14:23:52,713 ERROR [org.jboss.as.controller] (pool-2-thread-20) Operation ("read-children-resources") failed - address: ([("subsystem" => "osgi")]) - failure description: "child-type may not be null."
14:23:54,465 ERROR [org.jboss.as.controller] (pool-2-thread-19) Operation ("read-children-resources") failed - address: ([("subsystem" => "osgi")]) - failure description: "child-type may not be null."
14:23:58,297 ERROR [org.jboss.as.controller] (pool-2-thread-20) Operation ("read-children-resources") failed - address: ([("subsystem" => "osgi")]) - failure description: "child-type may not be null."
14:23:59,124 ERROR [org.jboss.as.controller] (pool-2-thread-20) Operation ("read-children-resources") failed - address: ([("subsystem" => "osgi")]) - failure description: "child-type may not be null."
14:24:02,680 WARN [org.jboss.as.protocol] (pool-2-thread-25) Got error closing channel JBREM00206: Channel is not open

while suddenly I can can do again :

[standalone@192.168.105.1:9999 subsystem=xxx] :read-resource
{
"outcome" => "success",
"result" => {
"activation" => "LAZY",
"module" =>

{ "com.xxx" => undefined, "com.xxx" => undefined }

}
}