I am trying to get the ZoneId of the webparts on a page, but when debugging the code that property contains this error:

‘webpartDefinition.ZoneId’ threw an exception of type ‘Microsoft.SharePoint.Client.PropertyOrFieldNotInitializedException’

Here is my code

    public void TestGetWebPart()     {         using (_clientContext = new ClientContext(Url))         {             _clientContext.Credentials = _credentials;             var web = _clientContext.Web;              var file = web.GetFileByServerRelativeUrl("/subsite/SitePages/Home.aspx");              var limitedWebPartManager = file.GetLimitedWebPartManager(PersonalizationScope.Shared);             var webPartDefinitions = limitedWebPartManager.WebParts;              _clientContext.Load(webPartDefinitions);             _clientContext.Load(limitedWebPartManager);              _clientContext.ExecuteQuery();              foreach (var webpartDefinition in limitedWebPartManager.WebParts)             {                 _clientContext.Load(webpartDefinition);                 _clientContext.Load(webpartDefinition.WebPart);                 _clientContext.ExecuteQuery();                  Console.WriteLine($  "{webpartDefinition.WebPart.ZoneIndex} - ");             }              var webPartDefinition = limitedWebPartManager.ImportWebPart(_scriptEditorXml);             limitedWebPartManager.AddWebPart(webPartDefinition.WebPart, "", 0);         }     } 

I tried “loading” the property with

_clientContext.Load(webpartDefinition, w => w.ZoneId); 

but it just says

‘WebPartDefinition’ does not contain a definition for ‘ZoneId’ and no extension method ‘ZoneId’ accepting a first argument of type ‘WebPartDefinition’ could be found (are you missing a using directive or an assembly reference?)

Even though I can see it in the debugging window:

How is this even possible?