SharePoint的ClientContext中的Server Version, Site, Web抛出错误

我是sharepoint新手。我试图上传一个文件，并将元数据添加到文件。下面是我的代码。在声明ClientContext

时，我可以看到一些内部异常

例外: clientContext结构。ServerVersion抛出类型为PropertyOrFieldNotInitializedException的异常

同样的情况也发生在Site, Web.

using (ClientContext clientContext = new ClientContext(SPURL))
{
    //ClientContext clientContext = new ClientContext(SPURL);
    clientContext.Credentials = new System.Net.NetworkCredential(userName, password, domain);
    Web web = clientContext.Web;
    FileCreationInformation newFile = new FileCreationInformation();
    newFile.Content = System.IO.File.ReadAllBytes(PPTPath);
    newFile.Url = "F:''log.txt";
    List docs = web.Lists.GetByTitle("Test");
    Microsoft.SharePoint.Client.File uploadFile = docs.RootFolder.Files.Add(newFile);
    clientContext.ExecuteQuery();
    using (FileStream fileStream =
                new FileStream(PPTPath, FileMode.Open))
        ClientOM.File.SaveBinaryDirect(clientContext,
        DocumentRepository + PPTfilename, fileStream, true);   
}