How to format data for import from a Mac?

If you work on Mac OS, to format your data to import, you must use the free suite Libre Office downloadable here:
https://fr.libreoffice.org/download/libreoffice-fresh/?type=mac-x86_64&version=5.0&lang=en .

Then follow the procedure for saving the CSV file as appropriate.

For the assisted import of contacts and/or companies linked to the CSV format :
http://www.simple-crm-support.com/2016/10/comment-enregistrer-un-fichier-csv-avec.html

For other import modules :
http://comment-utiliser-simple-crm.blogspot.fr/2014/01/import-simple-crm-comment-enregistrer.html