Excel documents are stored in our sharepoint portal.
We are looking to open excel workbook using Aspose cells from sharepoint, update worksheet Tab from datatable and save back to original sharepoint location.
Well, you must have FileIOPermission to access and create/recreate files. And please set CellsHelper.FontDir property, otherwise we could not get the font settings or you would find other issues.
You may try the following code with Aspose.Cells for .NET @ SharePoint:
Moreover, if you need to convert Excel file fomats, you should use our specific Aspose.Cells for SharePoint component for the environment, see the documentation for your refernece: