What code ? Did you reboot by chance ? Shouldnt be required to but you know how it goes ..
"Satisfaction does not come from knowing the solution, it comes from knowing why." - Rosalind Franklin
If you are trying to open WLC from a client who is connected to an AP managed by same WLC's, you may have to enable the Mgmt Via Wireless option to open the Management Via Wireless page from client.
You can enable it via CLI from the following command :
config network mgmt-via-wireless enable
OR do it from GUI from :
Step 1 Choose Management > Mgmt Via Wireless to open the Management Via Wireless page.
Step 2 Select the Enable Controller Management to be accessible from Wireless Clients check box to enable management over wireless for the WLAN or unselect it to disable this feature. The default value is unselected.
Step 3 Click Apply to commit your changes.
Step 4 Click Save Configuration to save your changes.