4. It is possible that you need to disable the pop-up blocker of the browser in order to view the online help.
These are things that you can check if the issue still occurs:
Check that the correct IP address and mask are on the Management interface.
Check that the switch, which connects to the WLC, has the native VLAN set correctly.
Check that the management interface and AP management interface VLANs are set correctly or are ideally left at the default, which is untagged VLAN (VLAN 0 on the WLC). Also, by default, only https access is enabled. If you want to enable http access, you have to type the config network webmode enablecommand from the controller CLI.