Take a screenshot of the issue.
If you are expecting to be assigned to a role based on group, make sure you have the group specified as domain\\group instead of domain\group.
My original reply was intended if you were using NTLM AND the box for "include domain name in group name" was checked.
Since you are using LDAP, you do not need to include the domain name in the group you specify.
If you are still having problems, I would guess it is related to your LDAP settings instead.
What kind of LDAP server is it?