We have an Excel application that I need to maintain that has shown his limitation of 65536 lines maximum in a sheet. I want to upgrade this application to an xml worksheet (.xlsx) to boost this limitation to 1 million. My solution is already targeting .Net 4.0 and using VSTO 4.0.
I tried Tools => Options => Office Tools => Project Upgrade => office 2007 Open XML format but nothing happen.
I tried creating a new Excel 2007 Workbook project and using the existing excel file (.xls). It shows an error box that says that the workbook contains activeX controls.