Dear Punit
It's caused by quite deep nesting of complex formulas, even Google sheets displays #REF! in that cell. I would look further into it
Meanwhile If you using it as a read only spreadsheet, then you can use this code to remove formulas upon importing the excel file into a workbook and before importing into pqgrid, that way the value would be displayed correctly.
pq.excel.eachCell(wb.sheets, function(cell){
cell.formula = null;
})