The spatial reference of the web scene or web scene layer is unsupported.
In a local 
scene, geographic coordinate systems are not supported. In a global 
scene, China Geodetic Coordinate System 2000 is not supported when sharing a web scene prior to ArcGIS Enterprise 10.8.
Custom coordinate systems are not supported when sharing a web scene prior to ArcGIS Enterprise 10.9.
Solution
If the local scene is in a geographic coordinate system, change the local scene to a global scene. On the View tab, in the View group, click Global .
Change the spatial reference of the scene to a supported coordinate system that has a Well Known ID.
More information
When sharing a web scene layer or a web scene, the coordinate system of the scene is used. WGS 84 and other geographic coordinate systems are not supported in a local scene and global scenes with China Geodetic Coordinate System 2000 are not supported in ArcGIS Enterprise prior to version 10.8.