Hello to all.
I had a similar situation. The problem was Microsoft Excel related. It does not correctly save some values in csv format.
1. The problem with the date - in Excel, the date is displayed normally, for example, 2015-09-27, but when you save it in csv format (or load it into Prestashop - then it converts to csv format itself), the date there is already not displayed correctly 09/27/2015 . Naturally, an error occurs during import.
2. Problem with email, or other fields. I was associated with the presence of specific characters inherent in the Norwegian language (ø é), etc. In this situation, the email did not validate upon import.
In general, the problem was purely in Excel and its work with csv. The problem was solved in this way. First I set up the whole file in the right form in xlsx format. Further, through the website, the envelope converted everything into csv. Then the import was successful. Perhaps you can configure Excel itself so that everything is correct, but I did not succeed. Therefore, I had to do a little harder.