My iCloud Calendar was not able to generate invitations on my Mac. I cleared the plists and the functionality briefly came back.
I found a solution I believe and that was to create a second iCloud calendar and export and import all my appointments to it.
So far Calendar invitations are once again available in the Calendar App.
I found a solution I believe and that was to create a second iCloud calendar and export and import all my appointments to it.
So far Calendar invitations are once again available in the Calendar App.