Export to Excel doesn't work on my Win 10/Office 365 Excel either. This is a recent decrement in feature because it worked in February of 2018 when I first built the spreadsheet model that I want to update. I was looking for answers and found the issue with Mac being discussed but wanted to point out that the export to Excel on PC is no longer an option (it is grayed out, only a .csv export is an option). This is a huge issue because I can no longer update my dependent Excel business analysis models.