With the latest available version of Royal, VC, and VC addon-ons the Advanced Button and Button 2 will not allow me to set a URL and Title.
I have configured a second test site with WordPress 4.2.2, Royal, and ALL default settings and have the same issue on this test site.
This is likely the same issue as the following post, but it is closed to replies:
https://www.8theme.com/topic/advance-button-url-undefined/
Can you please tell me how that post was resolved? Can provide access to the test copy I configured if needed.