For guest self-registration through RansNet HSG captive portal, HSG has a feature to verify user registered email address. eg. after user submits registration details (email compulsory), HSG will send a verification email to registered email address and open 10 minutes free access, so that user can have a temporary Internet to check their email and click on the validation link. Upon successful validation, user gets permanent access and their profiles (email) will be added into HSG database for future login, and venue owners can use the collected verified email for market campaigns and security trace-back etc. (see video demo https://youtu.be/_tUi5Atwi-c)

When using HSG local portal for user self-registration with email OTP, some devices can get a blank page when click on the validation link (at 1:12 of above demo video). This is because the devices use mobile data to resolve the validation link (depends on different device behavior), so it connects to a cloud URL instead of local portal. 

In order to address such issue, if the portal requires email OTP feature, please configure hotspot-portal URL to use captive.ransnet.com. For example, typically we use something like

Just change above to