Fixed in patch 3.10c of the ArcGIS Online November release.
対処法
Avoid adding basemaps via the ‘Esri Maps’ button.Use command line to add basemap. Command: ESRI_ADDMAPSERVICEBYURLURL: <a href="http://server.arcgisonline.com/arcgis/rest/services/ESRI_Imagery_World_2D/MapServer" target="_blank">http://server.arcgisonline.com/arcgis/rest/services/ESRI_Imagery_World_2D/MapServer</a>