FTP Uploading (Error=500) on big-files

[pcdrivers]

I have recently migrated to Cobian Reflector, importing the old Cobian Backup 11 jobs for several different systems.

I have tested different types of FTP servers in different services, from Synology and Western Digital NAS, or dedicated server ftp servers like Pure-Ftpd.

And the problem occurs when we try to upload files larger than 500mb. Apparently it uploads the complete file, but with errors. And in Cobian Reflector it gives the following error:

ERR 2022-07-20 04:48:44 An error occurred while loading the file "D:\Backups\Gestion\GESTION.zip" to "/Gestion": Unknown command (code=500)

Log from Pure-ftpd appear OK. But when trying to open the file, many errors on file.

Jul 20 04:48:44 ****** pure-ftpd: (******@******) [NOTICE] /home/******/GESTION 2022-07-20 04;36;17 (Completo).zip uploaded (1506109261 bytes, 2032.24KB/sec)

However, for small compressed files, or copying entire folders with small files, we did not encounter any problems.

[cobian]

Perhaps it's a timeout problem? Try activating the Keep alive command both for the data and the command channels.

[pcdrivers]

Not appear to be timeout problem.
It is difficult to determine the problem.
Those options were already active.

[pcdrivers]

Perhaps it's a timeout problem? Try activating the Keep alive command both for the data and the command channels.

Never solved...