Error: file already closed after a post-task error

Below are the logs from a failed transfer. The line with level warning should not be there: it seems to indicate an internal error (the file is closed several time) that should be handled in code, and not by the user.

2020/10/02 09:12:50 [INFO    ] sftp_server: Upload of file 'test02.txt' requested by 'myuser' using rule 'sftp_recv'
2020/10/02 09:12:50 [INFO    ] sftp_server: Transfer was given ID n°29
2020/10/02 09:12:50 [INFO    ] Pipeline 29: Beginning transfer n°29
2020/10/02 09:12:50 [INFO    ] Pipeline 29: Executing pre-tasks
2020/10/02 09:12:50 [INFO    ] Pipeline 29: Executing post-tasks
2020/10/02 09:12:50 [ERROR   ] Pipeline 29: Task TRANSFER @ sftp_recv POST[1]: failed to retrieve rule 'send_sftp': the record does not exist
2020/10/02 09:12:50 [WARNING ] Pipeline 29: Failed to close file '/var/lib/waarp-gateway/work/test02.txt.tmp': file already closed
2020/10/02 09:12:50 [INFO    ] Pipeline 29: Executing error tasks
2020/10/02 09:12:50 [INFO    ] Pipeline 29: Transfer finished, saving into transfer history
2020/10/02 09:12:50 [ERROR   ] Pipeline 29: Execution finished with error code 'TeExternalOperation'