private TransferOperationResult PutFile(string fileName, bool isImage, string imagePath, TransferOptions transferOptions, Session session)
{
   var localPath = fileName;
   var remotePath = _practiceSettings.remotePath;
 
   if (isImage)
   {
      localPath = $"{imagePath}{fileName}";
      remotePath = _practiceSettings.remoteImagePath;
   }
 
   return session.PutFiles(localPath, remotePath, false, transferOptions);
}

> 2021-02-26 08:38:04.771 Script: put  -nopermissions -nopreservetime -transfer="binary" -- "C:\MaskedFilePath\56343932-52d7-ea11-8104-0050568c65a2.pdf" "/"
. 2021-02-26 08:38:04.772 Copying 1 files/directories to remote directory "/" - total size: 151,921
. 2021-02-26 08:38:04.772   PrTime: No; PrRO: No; Rght: rw-r--r--; PrR: No (No); FnCs: N; RIC: 0100; Resume: S (102400); CalcS: No; Mask: 
. 2021-02-26 08:38:04.772   TM: B; ClAr: No; RemEOF: No; RemBOM: No; CPS: 0; NewerOnly: No; InclM: ; ResumeL: 0
. 2021-02-26 08:38:04.772   AscM: *.*html; *.htm; *.txt; *.php; *.php3; *.cgi; *.c; *.cpp; *.h; *.pas; *.bas; *.tex; *.pl; *.js; .htaccess; *.xtml; *.css; *.cfg; *.ini; *.sh; *.xml
. 2021-02-26 08:38:04.773 File: 'C:\MaskedFilePath\56343932-52d7-ea11-8104-0050568c65a2.pdf' [2021-02-26T11:31:16.087Z] [151921]
. 2021-02-26 08:38:04.773 Copying "C:\MaskedFilePath\56343932-52d7-ea11-8104-0050568c65a2.pdf" to remote directory started.
. 2021-02-26 08:38:04.773 Binary transfer mode selected.
. 2021-02-26 08:38:04.773 Starting upload of C:\MaskedFilePath\56343932-52d7-ea11-8104-0050568c65a2.pdf
> 2021-02-26 08:38:04.773 TYPE I
< 2021-02-26 08:38:04.809 200 Type set to I.
> 2021-02-26 08:38:04.809 PASV
< 2021-02-26 08:38:04.844 227 Entering Passive Mode (18,189,48,115,20,165).
> 2021-02-26 08:38:04.844 STOR 56343932-52d7-ea11-8104-0050568c65a2.pdf
. 2021-02-26 08:38:04.845 Connecting to 18.189.48.115:5285 ...
< 2021-02-26 08:38:04.881 550 Access is denied. 
. 2021-02-26 08:38:04.881 Copying files to remote side failed.
* 2021-02-26 08:38:04.881 (ExtException) **Copying files to remote side failed.**
* 2021-02-26 08:38:04.881 Access is denied. 
. 2021-02-26 08:38:04.881 Asking user:
. 2021-02-26 08:38:04.881 Error transferring file 'C:\MaskedFilePath\56343932-52d7-ea11-8104-0050568c65a2.pdf'. ("Copying files to remote side failed.","Access is denied. ")
< 2021-02-26 08:38:04.881 Script: Error transferring file 'C:\MaskedFilePath\56343932-52d7-ea11-8104-0050568c65a2.pdf'.
< 2021-02-26 08:38:04.882 Script: Copying files to remote side failed.
 
< 2021-02-26 08:38:04.882 Access is denied.
* 2021-02-26 08:38:04.882 (ESkipFile) Error transferring file 'C:\MaskedFilePath\56343932-52d7-ea11-8104-0050568c65a2.pdf'.
* 2021-02-26 08:38:04.882 Copying files to remote side failed.
* 2021-02-26 08:38:04.882 Access is denied. 
. 2021-02-26 08:38:04.882 Copying finished: Transferred: 0, Elapsed: 0:00:00, CPS: 0/s
. 2021-02-26 08:38:04.882 Script: Failed

try
{
   //LogHelper.LogTrace(string.Format("Sending file '{0}' to client server.", fi.FileName));
   TransferOperationResult transferResult;
 
   var isImage = !fi.FileName.EndsWith(".xml");
 
   transferResult = PutFile(fi.FileName, isImage, imagesScrPath, transferOptions, session);
 
   //retry once if failure
   if (!transferResult.IsSuccess)
   {
      LogHelper.LogTrace($"First upload attempt of file '{fi.FileName}' failed for practice {_practiceSettings.practiceName}. Re-trying upload.");
      transferResult = PutFile(fi.FileName, isImage, _practiceSettings.remoteImagePath, transferOptions, session);
   }
 
   //check FTP result. if this fails, it goes into the catch below to log for upload error and increment the failed counter
   //transferResult.Check();
 
   if (!transferResult.IsSuccess)
   {
      LogHelper.LogError($"Second upload attempt of file '{fi.FileName}' failed for practice {_practiceSettings.practiceName}. Marking as failed.");
      failCount += 1;
      continue;
   }
 
   LogHelper.LogTrace($"Successfully uploaded file '{fi.FileName}' to client server for practice {_practiceSettings.practiceName}.");
   successCount += 1;
}
catch (Exception ex)
{
   var logMsg =
      string.Format("\r\n{0}\t{1}\tError uploading {4} file '{2}' in ftpFile. Continuing: {3}",
         DateTime.Now.ToShortDateString(),
         DateTime.Now.ToLongTimeString(),
         fi.FileName,
         ex.Message,
         this._practiceSettings.practiceName);
   LogHelper.LogError(logMsg, ex);
   failCount += 1;
}