Running Arc GIS Pro 3.0.3
Hello! I'm trying to find out the total amount of build volume within a country. I have a global dataset which I am cropping using polygons for national boundaries.
Clip Info:

Visualization:

The issue is when I try to find the sum of values in the band using the Summary Statistics tool I receive ERROR 000229.

Is there some mistake that I am making? or is there perhaps a better way of doing this? any help would be much appreciated!
Additional info:
The attribute table is grayed out. I've tried using the build raster attribute function, while the task completes successfully it does not create an attribute table, or if it does I cannot locate it as the attribute table symbol is still grayed out and ctrl + t does not seem to do anything.

The data I'm using for the polygons comes from here: https://hub.arcgis.com/datasets/WorldPop::national-boundaries-1km/about
and the population and build density data originates from: https://ghsl.jrc.ec.europa.eu/download.php