The cause appears to be the use of non-ASCII characters in file names. Microsoft describes it like so: “Any user may be ...

Picture this: you've created an all-singing-all-dancing Microsoft Excel workbook, but when you share it with others, they have no idea where to start. That's why you need a homepage worksheet that ...

Microsoft is working to resolve a known issue that prevents some users from opening Excel email attachments in the new Outlook client.