PROBLEM
After updating to version 3.4 LDAP logins are no longer working!
SOLUTION
Libra Esva version 3.4 introduced several enhancements to the authentication system. Now Libra Esva manages per domain authentication.
Default authentication is always set to Local, and all existing domains has this default authentication scheme.
All LDAP Sets are still there and still working, the only thing you have to do is to define the authentication method for the domain, and set it to LDAP.
Go to menù System->Web Portal Domain Authentication, edit the domain properties and set it to LDAP.
IMPORTANT: With version 3.4 the username must be always the user email address. This is to allow Libra Esva extracting the domain the user belongs to, and look for the authentication method set above.
More information about the new authentication scheme can be found here.