I have complex, macro-enabled Excel (xlsm) files that work fine on OneDrive for Business as long as the "Use Office application to sync Office files that I open" is NOT checked in the OneDrive settings. The Office sync functionality and ability to work collaboratively is great, but it doesn't work with my (and others as I found while searching for my issue) workbooks. The file has backup and save macros and slows down immensely and throws strange errors for my clients ("High service activity", "File wasn't uploaded because we cannot merge change made by another user" when there is only one user, etc) making the files unusable unless they turn off Office syncing. If I could programatically exclude my specific xlsm file from being shared it would make a lot of people (especially me) happy. Or maybe exclude certain file types from syncing using the "Office applications" option. Having the ability using VBA would provide the best granularity. Thanks for your consideration.