Just upgrade software on my WLC5508 from 184.108.40.206 to 220.127.116.11 via GUI interface.
The upgrade was successfully,I can login to WLC.The other 2 WLC also upgraded to the same version and works.
The only issue,for Guest Vlan user didt get IP address and web login page.
Then we decide to revert to old image and working normally
Do you have any suggestion how to troubleshoot it?
I seemed to stumble across a lot of bugs in 7.3 and 7.4 - your symptoms are similar to one I found.
Have a look at CSCua39580 - WebAuth Fails post upgrade to 18.104.22.168
If you have an anchor controller (it's not clear from your post) then the work around is run the main 5508 on 7.3 and the anchor on 7.2.
After working for many weeks with Cisco, they finally released an enginneering version of 7.3 on, or about, 22-Feb-2013.
Try searching for "Addendum Release Notes for Cisco Wireless LAN Controllers and Lightweight Access Points for Special Build 22.214.171.124"
I never did try this version as it would have required a costly MSE upgrade and I'd lost my Mojo for all things wireless by that point.