After applying fix for -OPENIDM-9976- which resolves the blank page due to a UI dependency error, the following error is reported:

SecurityError (DOM Exception 18): Blocked a frame with origin "https://localhost:8443" from accessing a frame with origin "https://mail.google.com". Protocols, domains, and ports must match.

This is due to the fact that safari appears to have stricter rule with respect to CORs. The only way to see the page is to disable Cross-Origin Restrictions from the Developer menu which is not an option for your standard user.

Here are the steps to reproduce:

Steps to reproduce (IDM 5.0.0):

1. Configure Email in system preferences - http://localhost:8080/admin/#settings/email/
   1. I used gmail
2. Enable User Registration - http://localhost:8080/admin/#selfservice/userregistration
3. enable Email Validation
4. enable KBA Stage
5. From the Self-Service UI, using safari in private mode
   1. Register some user - http://localhost:8080/
   2. From within the same safari browser, open email client
   3. Open the registration email and click on (not copy/paste) link from registration email
   4. new tab is opened but is a blank page
   5. if you disable COR you will see the security answers as expected

On MacOS Sierra 10.12.6
Safari Version 10.1.2 (12603.3.8)