Insert Column: COM object that has been separated from its underlying RCW cannot be used

Dear all,

I have a workflow that use the combination on Excel Application scope and Excel Process scope both and I used a lot of Data manipulation to get the perfect datatable in the Excel application scope. After the end of excel application scope I started the excel process scope to make changes to format sheet mainly because the data in datatable is like 12-12 and getting converted into date while write range so process scope helped in changing the format of the whole sheet before writing the data. Now in process application scope I am getting the COM error on different activities sometime on format cell or sometime on Insert column. Not sure how to solve it. i tired adding delays also but it sometime works and sometimes not. Please suggest.