set discovery-agent enableI would also check the ap cert check on the vSCG as sometimes if this is enabled it will stop the AP from joining:
vSCG# show running-config ap-cert-checkIf you have a firewall, ensure that that LWAPP and SSH ports are made available.
AP Certificate Check: Enabled
vSCG(config)# no ap-cert-check
Do you want to continue to disable (or input 'no' to cancel)?
vSCG# show running-config ap-cert-check
AP Certificate Check: Disabled