If you’re able to SSH to your ZD, login with your admin credentials and you can reset your certificate thru the command
interface. This will restart your ZoneDirector after certificate is reset.
ruckus> en
ruckus# config
ruckus (config)# certificate
ruckus (config-certificate)# restore
ZoneDirector will restart now to apply the changes in the certificate settings.
[ and you lose your connection ]
Run a continuous ping from a DOS command prompt window, until your ZoneDirector
replies again, when you can try the HTTPS WebGUI once more.