Modify the JMX subsytem via CLI using the below command :
~~~
[domain@localhost:9990 /] /profile=full/subsystem=jmx/remoting-connector=jmx:add(use-management-endpoint=true)
~~~
Use the model browser of the admin console:

1. Open the model browser by selecting 'Management Model' from the tools menu in the footer
2. Navigate to profile => full / subsystem => imx / removing-connector
3. Add a new child resource (provide a dummy name like 'foo', when asked for the name of the resource)

The default domain.xml in EAP 7 contains:
~~~
<!-- <remoting-connector use-management-endpoint="false"/>-->
~~~

1) Start JBoss EAP 7.0.1 and open the management console at : https://127.0.0.1:9990/
2) Migrate to Configuration > Profiles > Profile: full > Subsystem: JMX.
3) Edit the configuration to change "Use Management Endpoint" to true(false by default).

An unknown error is reported as shown in the screeshot(ErrorScreen.png).

However, the below CLI command works :
~~~
[domain@localhost:9990 /] /profile=full/subsystem=jmx/remoting-connector=jmx:add(use-management-endpoint=true)
{
"outcome" => "success",
"result" => undefined,
"server-groups" => {"main-server-group" => {"host" => {"master" => {
"server-one" => {"response" => {"outcome" => "success"}},
"server-two" => {"response" => {"outcome" => "success"}}
}}}}
}
~~~

Now, if you try to edit the configuration(on the same profile) via admin console, it works.