Problem⌗

Unable to resolve users with either the standard user checker or the people picker (the people picker could also be that it hasn’t been configured for your provider so check that too) but users are being authenticated.

Solution⌗

If you have specified that your FBA connection string is to use integrated security then make sure that you have granted access not only for the machine but also the SharePoint farm account and the account which is running the SharePoint sites application pool