Application Server Control has no routing relationship with the Oracle HTTP Server by default. We have to make that relationship.
To do the modification you have to edit the "default-web-site.xml" file with the below change.
The file is located in the below location with in the server.
make the ohs-routing="true", by default this will be set to "false".
Bounce the server and try to launch the enterprise manager then try to login.
If the above solution is not working then try to change an entry in the server.xml file which is located in the same location.
The file is located in the below location with in the server.
In the file change the below property to true and bounce the server.
application name="ascontrol" path="../../home/applications/ascontrol.ear" parent="system" start="true" /
Now try launching the enterprise manager and login to the server. You should be able to see the AS control page now.