I'm using @Html.Glass().Editable(Model, x => x.MyProperty) for some of our single-text / rich text fields. When I load the site with this code in the view everything looks fine. However, when I open the Experience Editor I see this error:

Value cannot be null. Parameter name: objectToSwitchTo.

   at Sitecore.Diagnostics.Assert.ArgumentNotNull(Object argument, String argumentName)
   at Sitecore.Common.Switcher`2.Enter(TValue objectToSwitchTo)
   at Glass.Mapper.Sc.GlassHtml.MakeEditable[T](Expression`1 field, Expression`1 standardOutput, T model, Object parameters, Context context, Database database, TextWriter writer)

I've seen a few other SO threads about this but no real solutions for me. I'm using a data source set on the rendering. I've stepped through the entire process and don't see any null attributes in my model after using GetDataSourceItem<MyClass>. However, one thing I noticed is that my Sitecore ID field is all zeroes. I saw a different error prior to this, saying I needed to add a Sitecore ID field to my model, so I did. My code for the ID field is as follows:

    public virtual Guid Id { get; }

My Glass version is which I believe is still pretty recent.

  • If I change my definition of the Id field to { get; set; }, it works...
    – Paul
    Oct 3, 2018 at 22:29
  • 2
    You need a setter for the Id field so Glass can map your model back to Sitecore Item. From what I remember, the setter doesn't have to be public. [SitecoreId] public virtual Guid Id { get; private set; } should do the trick.
    – Marek Musielak
    Oct 4, 2018 at 5:50
  • It's funny because I tried private set first and it still didn't work. Regardless, it seems like I've found a solution to the problem - using { get; set; }.
    – Paul
    Oct 4, 2018 at 21:54

1 Answer 1


The fact I was getting an empty ID made me think that maybe Glass wasn't able to set the item ID on the property, so I changed my field definition from:

public virtual Guid Id { get; }


public virtual Guid Id { get; set; }

Now things are working fine.

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