Access is denied on GetFile

"Access is Denied" error occurs when attempting to download a file from a FTP site. Connection to the site is successful. What is denied? The file on the ftp or the folder where the file is to be downloaded?

If it's a permissions issue, then why is connecting to the site successful?

Code: Dim extractPath As String = "xxx"

    If Not Directory.Exists(extractPath) Then
        Directory.CreateDirectory(extractPath)
    End If

    Dim ftp As New Chilkat.Ftp2

    Dim success As Boolean
    success = ftp.UnlockComponent("cccc")

    If (success <> True) Then
        FTPFailure(ftp.LastErrorText, String.Empty)
    Else
        ftp.Hostname = "xxx"
        ftp.Username = "yyy"
        ftp.Password = "zzz"

        '  Connect and login to the FTP server.
        success = ftp.Connect()
        If (success <> True) Then
            FTPFailure(ftp.LastErrorText, String.Empty)
            Exit Sub
        End If

        '  Change to the remote directory where the file will be uploaded.
        success = ftp.ChangeRemoteDir("/")
        If (success <> True) Then
            FTPFailure(ftp.LastErrorText, String.Empty)
            Exit Sub
        End If

        '  Download file to extractPath
        'SUCCESS RETURNS FALSE HERE.
        success = ftp.GetFile("aaa-bbb.png", extractPath)
        If (success <> True) Then
            FTPFailure(ftp.LastErrorText, String.Empty)
            Exit Sub
        End If
    End If

The folder is accessible on this computer thru windows explorer. Thanks for any help or advice.