Problem

When a user connect to the server directly with the user with which CFT is installed and then typed “exit”, the semaphore issue message started to fill the cft.out file and then the CFTMAIN crashed.

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CFTS10E File communication task error (Invalid Sem) _ Terminating
CFTS30I XTRK Information CFTTRK: semaphore error, terminating
CFTS10E File communication task error (End on error 3) _ Terminating
CFTI35I PID=554 CFTTRK Task ended (MQID=44138499)
CFTS12W Error code 00000043 _ CFT write messages to output stream
CFTS05E Error code 00000043 _ Trying to access CFTFIL asynch. semaphore
CFTI35I PID=28161 CFTTFIL Task ended (MQID=44531727)

+ 2019/03/05 16:51:22.398402 ? 554 CFTTRK + 2019/03/05 16:51:22.398450 ? 561 CFTTCOM sem_lock failed sem 8749057 errno = 22 (Invalid argument)
sem_lock failed sem 8749057 errno = 22 (Invalid argument)
+ 2019/03/05 16:51:22.398472 ? 561 CFTTCOM SISY: invalid sem_id (sypost). errno=22 (Invalid argument)
+ 2019/03/05 16:51:22.398473 ? 554 CFTTRK CFTS10E File communication task error (Message sending error (-2)) _ Terminating
SISY: invalid sem_id (sypost). errno=22 (Invalid argument)
===========

Resolution

The problem seems environment specific i.e. cft user is not a system user and that the Linux parameter RemoveIPC is set to yes in etc/systemd/logind.conf
For more details refer to following article:
https://knowledgebase.progress.com/articles/Article/semaphores-removed-when-user-logs-out-on-Linux-000086484