The following messages appeared in the XCOM output, and after it the file transfer stopped.
ICH409I 283-01C ABEND DURING RACINIT PROCESSING
CCSR010E XCOMSTSK S283 at 00000000 LMOD N/A CSECT N/A +N/A XCOM
XCOM SERVER
CCSR061I PSW: 00000000 00000000 070C1000 8525FC70
CCSR062I ILC: 02 INTERRUPT CODE: 0D
CCSR067I COMPLETION CODE S283 REASON CODE 0000001C
We had to restart the started tasks and the file transfer worked well again.
Release : 12.0
XCOM for z/OS
From the IBM doc: this is the explanation for S283-1C: PASSWRD or PHRASE specified did not conform to length requirements.
ICH409I 283-01C ABEND DURING RACINIT PROCESSING is an exclusively RACF message, noting an exclusively RACF abend code. IBM doc refers us to RACF message documentation. You should pursue this problem through your RACF support people.