Hi,
I have configured FBA using LDAP in SharePoint 2013. Its working Fine. But When I use PeoplePicker It resolves only the users Primary Site collection admin and Secondary Site Collection Admin (It does not resolve even Central Admin Configurable Account). I have added the users into userpolicy, but I'm unable to resolve the users and I got the error "Sorry, you are not allowed to share this with external users.".What is the issue and how to solve it?