Hello Dirk
This is true, previously i mis-informed that API flopping is helping, but this is not true, i forgot to restart service after.
So the current problem description may be summed up this way:
- when API is enabled, service wont start, main process fails with code 139.
- config validation shows no error or warnings
- there are no errors and one warnings for Listener in /var/log/icinga2:
# egrep -r -i error\|warn /var/log/icinga2/*
/var/log/icinga2/icinga2.log:[2020-09-10 16:32:24 +0000] warning/ExternalCommandListener: This feature is DEPRECATED and will be removed in future releases. Check the roadmap at https://github.com/Icinga/icinga2/milestones
/var/log/icinga2/icinga2.log:[2020-09-10 16:33:27 +0000] warning/ExternalCommandListener: This feature is DEPRECATED and will be removed in future releases. Check the roadmap at https://github.com/Icinga/icinga2/milestones
Whole RedHat server has been restarted.
I reinstalled icinga2, together with dropping DBs, but httpd left untouched.
In that process erased /etc/icinga2 (but not /var/lib/icinga2)