Grid to Excel

Call to Excel:<div><input type="button" value="Excel" onclick="mygrid.toExcel('/dhtmlx5/codebase/grid-excel-php/generate.php');">

However, no excel file is created. I’ve attached the XML error file created on the server which doesn’t show any obvious errors. Please advise.

Thank you.
error_report_2018_06_28__14_51_32.zip (1.22 KB)