Those are some custom rules of the server you are uploading to. You better contact the server administrators. We do not know those rules.

I am trying to upload an 837 billing file to LA County DMH through WINSCP, however, my file's keep failing for "duplicate control number found" control#000002387 file name LAC_DEC2020_Rebill.txt. I have tried resubmitting these files with updated CCN numbers but they continue to fail as "duplicate." This has happened to me several times and am hoping to be able to get these files to process as they need to be billed to LAC County DMH. Can someone advise how to get these files processed vs failed?