your icinga director is the unstable version from 14 Dec 2017. That’s bad!
you also mixed up icinga2 version with the icingaweb2 version, but at least we can see that your icingaweb2 is from Oct 2019.
but anyways, I hope this system is not a productive system.
Please make a backup and upgrade the machine to a more decent version and not the master build
Thank you very much for your advice. I will definitely take them into account. But first I urgently need a solution to my problem.
Do you have an idea ?
No because I won’t check out an unstable masterbuild from 2017 to try to reproduce your issue.
your best chance is to upgrade at least to the next stable release. If the issue persists you can ask again.
Or you undo all changes since the last good deploy, restore a backup or do it manually, but that’s even more work.