unsupported features in Office 365
If there are unsupported features when opening an Excel workbook for edit in Office 365, then please inform me what these features are and where to find these in the workbook, instead of 'To edit this in your browser, we will create a copy that doesn't include unsupported features.'
For instance I get specific information when saving an Office 97 version after editing in Office 2013.
This helps me to decide what to do: accept (e.g. is only a presentation issue) or somehow make it impossible to edit via Online (e.g. VBA code will get crippled).