Your map does not contain a basemap. Your map must contain a basemap to share it as a web map or a global scene.
Add a basemap.
- On the Map tab, in the Layer group, click Basemap.
- Choose a basemap from the gallery.
Web maps and global web scenes require a basemap to define the tiling scheme and spatial reference of the web map or web scene to ensure other web layers align correctly. All cached layers that have a tiling scheme must use the same tiling scheme as the basemap.