I'm sorry to hear that you were receiving this error. I took a look at your account and I see that you were able to import a few different files on the 22nd. Are you still having difficulty?
I managed to import some files, but not all. I am creating the files directly out of Legrand CRM. Could there be 'illegal' character within the file? Do you have a list of illegal character that I can search for?
I don't have any documentation on what illegal characters cause a file to fail importing. But I did open a case for your account and it's been escalated to our specialists who are going to follow up with you via email.
One thing to note for files is that normally a file will fail if the company and country fields are longer than 50 characters or the custom fields are longer than 255 characters.