ICCNE 2018 is not authorized to assist with the VISA process. The invitation letter from the organizing committees will be sent upon the request only when you register successfully, which may help but cannot guarantee you a France Visa.
We advise you to check as soon as possible with the French consular services in your country to know the list of documents required and the waiting period to obtain your visa (variable from one country to another).
Please note that the visa of French embassies and consulates are generally by appointment.
In case of refusal of visas by the French authorities, the ICCNE 2018 will not be held responsible if you are requested to cancel your participation to the conference.
You could check http://www.schengenvisainfo.com/france-visa/ for details information.