Don't use XLS, it's a very old file format. Try XL5 instead.

>Hello all,
>
>I wish you all to have a healthy and happy new year 2023!
>
>In my application I export some data to an excel file. The problem is that when I look at that created Excel file within the file explorer on my conputer everything is fine. The thing is that I open the file on my iPhone I receive an error message telling me that it can't be previewed.
>
>I export this way
>
>EXPORT TO FileExported TYPE XLS
>
>Is it only a problem of the extension XLS?
>
>I noticed that there is a class available to manage excel files. Would using it fix my problem?