This error occurs in FileZilla when trying to upload files to your FileX sFTP server.
First, make sure you are uploading to the correct file directory. Then, check to see if your file is named correctly. For patron loads, see the file naming conventions. If you have completed these steps and are still getting the error, contact OCLC Support with your OCLC symbol and a screenshot showing the full error messages.
Determine which upload directory to use
Is there a way to test patron loads?