I have a large-ish .xlsx file that I keep live on sharepoint for multiple users to view/edit and it suddenly is saying that it has 'Unsupported Features' and external links. I've searched the whole workbook for external links and I have not found references to an external workbook in any cell. I also have no idea what the 'Unsupported Feature' is that is not allowing the file to be edited in the browser version of excel. Because of the particular use case of the file, this is a problem. Is there any way to find out where it is seeing links and what the unsupported features are?