When opening a spreadsheet saved by the FYI for Office add-in, the following error displays:
"This workbook couldn't be opened because the file format may not be matching the file extension."
This error is caused when the default saving method in Microsoft Excel is set to a format different to the default .xlsx format of the FYI for Office add-in.
When saving spreadsheets via the FYI for Office add-in, the add-in currently sets the file extension to .xlsx creating a mismatch with the file extension.
The error can be resolved by users changing their default save settings back to .xlsx format in Microsoft Excel:
- In Microsoft Excel, click File and then Options.
- Navigate to Save.
- At the "Save files in this format:" option, select "Excel Workbook (*xlsx)".
Refer to Change the default file format for saving workbooks - Microsoft Support
This will resolve the issue for new spreadsheets saved via the add-in.
If users require a different format to .xlsx such as Excel Macro-Enabled Workbook (*xlsm) as their default file type, we recommend saving the document to a temporary location on your computer and then drag and drop them into FYI. This will retain the correct file extension. These spreadsheet can then be edited via FYI.
For existing workbooks where this error is occurring, we recommend exporting the file to a temporary location on your computer and then drag and drop back into FYI as a new document. This will retain the correct file extension and spreadsheets can then be edited in FYI.