A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
Hi
It sounds like you are trying to open the files using File > Open > Recent.
The recent file feature uses shortcuts to where your documents were located on the old Mac. The file paths are different now, so the shortcuts are broken. Use File > Open and search for your files using the search field in File > Open dialog, or locate your files in Finder and double-click them to open them. As you open your files, the recent list will learn the new locations.