Need help with custom script on site, that is not working

On one of my subsite I have custom script for map that also pulls members list when selecting state on map or in select. It should open popup where members are listed.
Right now popup opens, but returns no members for Alabama state (only state that has sample members).
In browser console script load.php returns 500 internal server error. We tried to fix that, because it was showing actual errors in error_log. But removing errors did not help, console still throws 500 internal server error but there is nothing in error_logs.

Details like link to site, to script on github and details about access are in attached chat link.