Sync-enabled hosted feature layers are incapable of deleting features in a Portal for ArcGIS web map when using ArcGIS Data Store that is installed while logged in as a user with a non 'month-day-year' region set in the Region and Language settings.
最後に公開された状態: September 9, 2016ArcSDE/Enterprise Geodatabase
Uninstall ArcGIS Data Store, log in as a user with the Region and Language settings set to English (United States), and reinstall ArcGIS Data Store.
Or
Edit the datestyle value in the postgresql.conf configuration file to 'iso, mdy'.