SanderLesage

/// <summary>
/// Create documentset from folder
/// </summary>
/// <param name="ctx">SharePoint clientcontext</param>
/// <param name="libraryUrl">web relative document library url</param>
/// <param name="documentSetName">name for the new document set</param>
/// <param name="documentSetContentTypeId">content type of the new document set. 
/// We assume that this content type is already binded to the document library.</param>
public ListItem CreateDocumentSet(ClientContext ctx, string libraryUrl, string documentSetName, string documentSetContentTypeId)
{

SanderLesage

using (var ctx = new ClientContext(webUrl))
{
    //get web and load required properties
    var web = ctx.Web;
    ctx.Load(web, w => w.SupportedUILanguageIds, w => w.TitleResource);
    ctx.ExecuteQuery();

    //change site title for all supportedUILanguages.
    var resource = web.TitleResource;
    foreach (var culture in web.SupportedUILanguageIds)