thanks but
i set culture:
[WebMethod]
public bool InsertDocument(bool isArticle, ArticleResponse item)
{
var provider = new TreeProvider(UserInfoProvider.GetUserInfo("myUser"));
CMS.DocumentEngine.TreeNode parent = provider.SelectSingleNode(CMS.SiteProvider.SiteContext.CurrentSiteName, "/ART", CultureHelper.GetDefaultCultureCode(CMS.SiteProvider.SiteContext.CurrentSiteName), true, "CMS.MenuItem");
TreeNode node = TreeNode.New("custom.Article", provider);
i use this code in web usercontrol and work very well. but when i use in webservice, this line get error
node.Insert(parent, true);
What is the problem?