I\'ve configured FBA with Sharepoint 2013 on my development machine (one server). I\'m able to create FBA Roles and FBA users and i can connect using FBA users.
The
I had the exact same issue. This was because the Users and Groups were'nt in the same OU. I was able to resolve this by adding userContainer="xxxxxx" in the role Provider
https://social.technet.microsoft.com/Forums/en-US/9592df6b-d789-49c0-b1ec-142828cdadc8/fba-ldap-domain-group-members-getting-access-denied?forum=sharepointadminlegacy