If you get this error on uploading the KML resource: it is probably because there are some empty values in your CSV file. To fix this:

1. Delete the KML file you just uploaded and any “Datastore” and “Web Map Service” files – see below – from your dataset

1. Download and edit your CSV file, removing any lines with empty latitude or longitude values
2. Run the CSV to KML converter again (CSV To KML Converter
3. Upload the new KML file (you should probably also replace the CSV file with the clean one you have just created)
4. Import the KML file to the Geoserver and Datastore again
5. Check for a successful load and that the map is displaying