If you are making use AppPool which is on .NET version 2.0 with 64 bit, then you need to modify the web.config in the location C:\Windows\Microsoft.NET\Framework64\v2.0.50727\CONFIG. Also ensure that you have modified the above highlighted section to 18.104.22.168.
Grant the permissions to the Network Service Account Write / Modify permissions to the C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Temporary ASP.NET Files\ folder. Note: depending on your AppPool framework and bitness the above path can differ.
Remember You don't need to have any settings at the FTP website level for the .NET Roles, .NET Users etc, Because the root web.config setting should apply to all the applications which run on that version of framework and bitness.