You have a .csv file that's located on Microsoft OneDrive or Microsoft OneDrive for Business. When you try to share this file with other people in Microsoft Excel, you receive the following message:
To collaborate with others, please save a copy of your file to an online location and change the file type to .xlsx.
This situation occurs even if the Use Office 2016 to sync Office files that I open feature is enabled on OneDrive.
This issue occurs because OneDrive doesn't treat .csv files as Office files. Therefore, the collaborative features that you expect to apply to Excel files aren't available when you work with .csv files on OneDrive.
To work around this issue, follow these steps:
- Save a copy of the .csv file as an .xlsx file on OneDrive.
- Open the .xlsx file in Excel, and then share the file as usual.
This behavior is by design.
The Use office 2016 to sync Office files that I open feature enables you to co-edit and share documents directly from Office applications, including Excel, Microsoft Word, Micrsoft PowerPoint, and Microsoft Visio.