Server side table not rendering rows

WeaponX86

Test url:
https://beta.propertypreswizard.com/test_scripts/beta/ajax_test.php

JSON dummy file:
https://beta.propertypreswizard.com/test_scripts/beta/ajax_sample.json

-Columns are defined server side and sent down in a separate AJAX call first which populates the table header.
-JSON data will have more columns than shown since some are hidden

WeaponX86

I found the problem, was passing back "sEcho: 0" in the JSON which DT didn't like. Didn't give any indication though so difficult to spot.