You are attempting to share a voxel layer as a web scene layer. However, the coordinate system of your scene does not match the coordinate system of the voxel layer.
Hover over the analyzer message. Click the Options button that appears and click Change Coordinate Systems Properties to open the Map Properties dialog box. On the Coordinate Systems tab, under the corresponding Coordinate Systems Available list, expand Layers. Select the coordinate system used by the voxel layer and click OK.
For more information, see Specify a coordinate system and Analyze your GIS resource.