I have a G930A, un-rooted, running AT&T's version of Oreo (8.0.0). I received an OTA update over the weekend and cannot use Google Calendar since--app force stops.
I also cannot do a calendar insertion from Tasker.
I have, of course reinstalled, cleared system cache, twiddled permissions, even factory reset, but am getting nowhere. Wife's phone has same update, but calendar is working fine.
Security patch level November 1, 2018