public void ConnectSFTP()
{
    // Set up session options
    SessionOptions sessionOptions = new SessionOptions
    {
        Protocol = Protocol.Sftp,
        HostName = SFTP_Host,
        PortNumber = SFTP_Port, 
        UserName = SFTP_UserID,
        Password = SFTP_Password,
        SshHostKeyFingerprint = SFTP_SshHostKeyFingerprint
    };
    sessionOptions.AddRawSettings("Cipher", "aes,chacha20,3des,WARN,des,blowfish,arcfour");
    session = new Session();
    session.ExecutablePath = ExePath;
        
    // Connect
    try
    {
        session.Open(sessionOptions);
        TraceLog.appendTransactionLog("Connected to " + SFTP_Host + ":" + SFTP_Port);
    }
    catch (Exception ex)
    {
        TraceLog.appendTransactionLog("Failed to connect to " + SFTP_Host + ":" + SFTP_Port + " (" + SFTP_SshHostKeyFingerprint + ")" + Environment.NewLine + "Error: " + ex.Message);
    }
}
 
public FileDownloadObj DownloadFiles(DateTime dt)
{
....
    ConnectSFTP();
 
    if (session.Opened)
    {
        using (session)
        {
            sssion.QueryReceived += (sender, e) =>
            {
                sLogText = string.Format("Error: {0}{1}", e.Message, Environment.NewLine);
                TraceLog.appendTransactionLog(sLogText);
                sErrMsg += string.Format("Error: {0}{1}", sLogText, Environment.NewLine); ;
                e.Continue();
            };
            // Transfer options
            TransferOptions oTrRes = new TransferOptions();
            oTrRes.TransferMode = TransferMode.Automatic; //The Transfer Mode - Automatic, Binary, or Ascii 
            oTrRes.FilePermissions = null;  //Permissions applied to remote files; null for default permissions. Can set user, Group, or other Read/Write/Execute permissions.  
            oTrRes.PreserveTimestamp = false;  //Set last write time of destination file to that of source file - basically change the timestamp to match destination and source files.    
            oTrRes.ResumeSupport.State = TransferResumeSupportState.Off;
 
            // Enumerate files to download
            DateTime dtYesterday = DateTime.Today.AddDays(-1);
            //IEnumerable<RemoteFileInfo> fileInfos2 = session.EnumerateRemoteFiles(sRemotePath, "APBS*.XML", EnumerationOptions.None).Where(file => file.LastWriteTime > dtYesterday);  // Chokes!
 
            IEnumerable<RemoteFileInfo> fileInfos = session.EnumerateRemoteFiles(sRemotePath, "APBS*.XML", WinSCP.EnumerationOptions.None);

// Enumerate files to download
DateTime dtYesterday = DateTime.Today.AddDays(-1);
 
/* This throws error  */
//IEnumerable<RemoteFileInfo> fileInfos2 = session.EnumerateRemoteFiles(sRemotePath, "AP*.XML", EnumerationOptions.None).Where(file => file.LastWriteTime > dtYesterday);
 
/* This works  */
IEnumerable<RemoteFileInfo> fileInfos = session.EnumerateRemoteFiles(sRemotePath, "AP*.XML", WinSCP.EnumerationOptions.None);