Available with Standard or Advanced license.
The spatial index associated with the mosaic dataset is non-default and possibly sub-optimal.
The spatial index of the mosaic dataset is different from the default computed spatial index.
If you have intentionally used custom spatial index values, you can ignore this warning.
If you want to use the default computed spatial index values, view the Indexes tab within the Mosaic Dataset Properties page. In the Spatial Index frame, you are able to delete the current spatial index, then create it with the system default.