Hi,
2 problems:
1. SSL
you have plugin called "SSL redirect", this plugin make a redirect only when menu item ID is set, we and many other components use ajax to get some request without ItemID and this generates mix content.
Joomla have own SSL configuration in Global Config->System, or in each menu item (so I think "SSL redirect" plugin is not helpful). Now I have disabled this plugin
2. MijoSEF (Maybe)
Twitter require a token to get Login/Permission App page, on your site this not work because you have some strange redirect due maybe from MijoSEF.
Example:
on your site if I go to:
https://www.modasocial.net/index.php?option=com_jsn&tmplsocial=1&view=twitter&task=requesttoken
I have redirect to:
https://www.modasocial.net/?task=requesttoken&tmplsocial=1&view=twitter (wrong)
on my site when I go to:
https://www.easy-profile.com/index.php?option=com_jsn&tmplsocial=1&view=twitter&task=requesttoken
I have correct JSON twitter response with code.
Try to contact MijoSef support to remove this redirect