Sitecore glass editable cannot convert lambda expr

问题:

I'm using Sitecore 7.5, MVC 5.2 and Glass Mapper 3.2.

When using Editable() in the renderings, the error below is shown in visual studio even though it renders properly when using the site and/or the page editor. Am I missing a reference or something?

Error:
"Cannot convert lambda expression to type 'System.Linq.Expressions.Expression>' because it is not a delegate type"

View

@using Sitecore.Mvc
@using Sitecore.Mvc.Presentation

@inherits Glass.Mapper.Sc.Web.Mvc.GlassView<Air.SitecoreModels.Metadata>

@*<h1>@Model.Item.Name </h1>*@

<h2>@Editable(x => x.BrowserTitle)</h2>

Model (auto generated with TDS)

[SitecoreType(TemplateId=IMetadataConstants.TemplateIdString )] //, Cachable = true 
public partial interface IMetadata : IGlassBase 
{
    /// <summary>
    /// The BrowserTitle field.
    /// <para></para>
    /// <para>Field Type: Single-Line Text</para>       
    /// <para>Field ID: 82cb07ca-0f04-442e-9a42-641d71540b35</para>
    /// <para>Custom Data: </para>
    /// </summary>
    [SitecoreField(IMetadataConstants.BrowserTitleFieldName)]
    string BrowserTitle  {get; set;}

                /// <summary>
    /// The PageTitle field.
    /// <para></para>
    /// <para>Field Type: Single-Line Text</para>       
    /// <para>Field ID: 462e2170-1157-4e9d-92dc-0d5da2956c44</para>
    /// <para>Custom Data: </para>
    /// </summary>
    [SitecoreField(IMetadataConstants.PageTitleFieldName)]
    string PageTitle  {get; set;}

}


[SitecoreType(TemplateId=IMetadataConstants.TemplateIdString, AutoMap=true)] //, Cachable = true
public partial class Metadata  : GlassBase, IMetadata 
{

    /// <summary>
    /// The BrowserTitle field.
    /// <para></para>
    /// <para>Field Type: Single-Line Text</para>       
    /// <para>Field ID: 82cb07ca-0f04-442e-9a42-641d71540b35</para>
    /// <para>Custom Data: </para>
    /// </summary>
    [global::System.CodeDom.Compiler.GeneratedCodeAttribute("Team Development for Sitecore - GlassItem.tt", "1.0")]
    [SitecoreField(IMetadataConstants.BrowserTitleFieldName)]
    public virtual string BrowserTitle  {get; set;}

            /// <summary>
    /// The PageTitle field.
    /// <para></para>
    /// <para>Field Type: Single-Line Text</para>       
    /// <para>Field ID: 462e2170-1157-4e9d-92dc-0d5da2956c44</para>
    /// <para>Custom Data: </para>
    /// </summary>
    [global::System.CodeDom.Compiler.GeneratedCodeAttribute("Team Development for Sitecore - GlassItem.tt", "1.0")]
    [SitecoreField(IMetadataConstants.PageTitleFieldName)]
    public virtual string PageTitle  {get; set;}                        
}