I’ve been attempting to troubleshoot some issues with sending Excel files back and forth between my Mac at home and a professor who uses a Mac at home and a Windows PC at school. Even though we’re both using current versions of Excel, and though the files opened fine on her Mac, she was having consistent problems on the Windows machine.
After a few days of back-and-forth and trying to narrow things down, here’s what I’ve come up with.
For some reason, though Excel:mac2008 (hey, that’s how the ‘About’ screen writes the product name, don’t blame me) uses the new XML-based file structure, when saving files, it uses the old standard
.xls file extension. Oddly, at least on my machine, it is behaving like this even though Preferences… > Compatibility > Transition > Save files in this format: is set to “Excel Workbook (.xlsx)”.
(And as an aside, why must there be an open workbook to access Excel’s preferences dialog box?)
Current versions of Excel on the Windows side of the fence, however, use (and expect) the
.xlsx extension. Same file types, but different extensions, and this causes confusion. When Excel (Windows) sees the
.xls extension, it expects a different type of data than it does when opening a document with the
.xlsx extension, and it chokes when attempting to open the file.
The solution? Manually change the extension to
.xlsx before e-mailing the file.