zurb foundation 5 top bar with asp net mvc 4 - css

Question

I work on an asp net mvc 4 solution working (well) with Zurb foundation 4.
I have to update it to the version 5 of the framework (the current version offers by Zurb is 5.3).
No problem for the moment^^.
But I have an issue with the top bar element with this new version (and the same with sub-nav).
The top-bar appears on my page but the dropdown lists don't work, in full screen as in responsive.
I already check some topics on it and add the "famous" data-topbar on the nav class="top-bar" but it still doesn't work.
I suspect that we won't make the upgrade on the solution if i can't fixed this problem, so I cracked on it for many hours...
Here is a sample of my HTML:
<nav class="top-bar" data-topbar>
<ul class="title-area">
<!-- Title Area -->
<li class="name">
<h1><i class="general foundicon-home"></i>TDB </h1>
</li>
<!-- Remove the class "menu-icon" to get rid of menu icon. Take out "Menu" to just have icon alone -->
<li class="toggle-topbar menu-icon"><span>Menu</span></li>
</ul>
<section class="top-bar-section">
<!-- Left Nav Section -->
<ul class="left">
#if (Request.IsAuthenticated && (! ViewUtils.UtilisateurCourant.IsInfi()))
{
<li class="divider"></li>
<li class="#classMandats">Mandats</li>
<li class="divider"></li>
<li class="#classContacts">Contacts</li>
<li class="divider"></li>
}
#if (Request.IsAuthenticated && (ViewUtils.UtilisateurCourant.IsSuperAdmin() || ViewUtils.UtilisateurCourant.IsAdmin()))
{
<li class="#classAdmin">Administration
<ul class="dropdown">
#*<li><label>Actions</label></li>*#
<li>#*<img src="~/Areas/Admin/Content/Utilisateurs/icons/group.png" class="MenuIcon" />*#Utilisateurs</li>
<li class="divider"></li>
<li class="has-dropdown">#*<img src="~/Areas/Admin/Content/Utilisateurs/icons/services.png" class="MenuIcon" />*#Prospect / Client
<ul class="dropdown">
<li>Statuts</li>
<li>Perte</li>
<li>Origines</li>
</ul>
</li>
<li class="divider"></li>
<li>Import prospects ImmoInversé</li>
<li class="divider"></li>
#{
//string urlProspectsClient = string.Concat(ViewUtils.GetBaseUrlSiteWeb(), "/Areas/Admin/Content/ReportingService/RapportV2.aspx?rapport=1");
string urlProspectsClient = Url.Action("Index", "MarketingStats", new {area = "Admin"});
}
<li>Rapp. Prospects/Clients</li>
#if (Request.IsAuthenticated && ViewUtils.UtilisateurCourant.IsSuperAdmin())
{
<li class="divider"></li>
<li>Moteur</li>
<li class="divider"></li>
<li>Nettoyage de la base de données</li>
}
</ul>
</li>
<li class="divider"></li>
}
If someone can help me it will be nice.