Prosites no longer sending sign-up confirmation emails or allowing new sign-up for sites.

Prosites no longer sending sign-up confirmation emails or allowing new sign-up for sites. This all worked fine before and no changes have been done on the main site except for the regular plugin updates.

Now it seems like everything has stopped working. Is this in anyway related to the recent Prosite and other updates and is there any known fix to return the site's sign-up/registration/login/confirmation emails functionality?