error message OOPS: child died

[GBfromCDA]

could somebody indicate me where I should look for solving this message.
below is the log.
thanks

2022-01-29 16:27 The log tab has been cleared. The log file with its full content is still available from the Log menu
2022-01-29 16:28 Preventing the system from entering sleep mode...
2022-01-29 16:28 ** Backing up the task "Backup database" **
2022-01-29 16:28 Counting the files for the task "Backup database"...
2022-01-29 16:28 If your unpacker cannot handle the archives created by Cobian Backup, see the FAQ
2022-01-29 16:28 Starting the Volume Shadow Copy snapshot for the drives: C:\
2022-01-29 16:28 The Volume Shadow Copy snapshot set has been created successfully
2022-01-29 16:28 Compressing to the archive "C:\Users\Server Location125\AppData\Local\Temp\Sauvegarde 2022-01-29 16;28;21 (Full).7z". Please wait while preparing the files...
2022-01-29 16:36 Connecting to
2022-01-29 16:36 TLS is not available on this server. Trying a plain connection...
2022-01-29 16:36 The user "Location125com" has initiated a session on
2022-01-29 16:36 Uploading the file "C:\Users\Server Location125\AppData\Local\Temp\Sauvegarde 2022-01-29 16;28;21 (Full).7z"
2022-01-29 16:36 Error uploading the file "C:\Users\Server Location125\AppData\Local\Temp\Sauvegarde 2022-01-29 16;28;21 (Full).7z": OOPS: child died

2022-01-29 16:36 Retrying the transfer of "C:\Users\Server Location125\AppData\Local\Temp\Sauvegarde 2022-01-29 16;28;21 (Full).7z"...
2022-01-29 16:36 Connecting to
2022-01-29 16:36 TLS is not available on this server. Trying a plain connection...
2022-01-29 16:36 The user "Location125com" has initiated a session on
2022-01-29 16:36 The remote directory has been changed to "/Location125_com"
ERR 2022-01-29 16:36 Error uploading the file "C:\Users\Server Location125\AppData\Local\Temp\Sauvegarde 2022-01-29 16;28;21 (Full).7z": OOPS: child died

2022-01-29 16:36 The history file for "Backup database" will not be saved because the result of the backup is empty
2022-01-29 16:36 Deleting the Volume Shadow Copy snapshot "ff227429-ccde-4499-b6ca-204d7e873786"
2022-01-29 16:36 The Volume Shadow Copy snapshot set has been successfully deleted
2022-01-29 16:36 Total backup time for "Backup database": 0 hours, 8 minutes, 54 seconds
2022-01-29 16:36 ** Backup done for the task "Backup database". Errors: 1. Processed files: 2. Backed up files: 0. Total size: 0 bytes **
2022-01-29 16:36 --
2022-01-29 16:36 The system can now enter sleep mode
2022-01-29 16:36 Total backup time: 0 hours, 8 minutes, 58 seconds
2022-01-29 16:36 *** Backup done. Errors: 1. Processed files: 2. Backed up files: 0. Total size: 0 bytes ***
2022-01-29 16:36 --

[cobian]

This is a ftp internal error. Often but not always caused by the Connection being disconnected or by a firewall blocking the data channel.