The Excel Workbooks, Excel Add-ins, and screencasts on this site will be updated and corrected regularly so head there if you are merely looking for the latest versions of a file. As far as mistakes ...

does anyone know if it is possible to write add-ins for Excel 2011 on the Mac? Preferably in C/C++/Cocoa, but almost any language would do. If so, pointers towards the SDK would also be appreciated.

Microsoft says the Excel spreadsheet software is now blocking untrusted XLL add-ins by default in Microsoft 365 tenants worldwide. The company announced this change in January with a new entry added ...