When the macro security settings are set to high or very high, a message box announces that macros can't be run and that this behaviour can be set in Extras/Optionen/LibreOffice/Sicherheit (in German).
This path for the settings might be correct for Windows or Linux, on MacOS however it is Einstellungen/LibreOffice/Sicherheit.
English message needs to be fixed.
Andras Timar committed a patch related to this issue.
It has been pushed to "master":
fdo#44698 settings are under a different menu in Mac OS X