Entity Framework store XML datatype ; "Unable to switch encoding" error

I am using Entity Framework version 6.0.0 in a C# Project that uses .NET Framework 4.5. I have a class Filing who has a SQL Server column XmlContent which is xml datatype. I have Database-first Entity Framework I am using primarily to save rows to the Filing table (I currently don't read those rows back, if that makes a difference)

I've read these posts regarding a "string" backing property to save to an XML column using Entity Framework, as described here and here

My XML declaration looks like this

<?xml version="1.0" encoding="UTF-8"?>
....

And my Entity Framework auto-generated (database-first) looks like this:

public partial class Filing
{
    // ...
    public string XmlContent { get; set; }
    // ...
}

With my custom partial class like this (saving to the string property...):

public partial class Filing
{
    [NotMapped]
    public XmlDocument XmlDocument
    {
        get
        {
            var xmlDocument = new XmlDocument();
            xmlDocument.LoadXml(this.XmlContent);
            return xmlDocument;

        }
        set
        {
            this.XmlContent = value.OuterXml;
        }
    }
    // ...
}

When I do this:

eFileEntities.Filings.Add(filingWithUtf8XmlString);
eFileEntities.SaveChanges();

I get an exception, whose InnerException (eventually), reads:

"XML Parsing : line 1 , character 38, unable to switch the encoding."

I've read these posts regarding the error I'm getting, "unable to switch the encoding"

• https://stackoverflow.com/a/8998183/1175496
• https://stackoverflow.com/a/1091209/751158
  • These answers suggest using a SqlXml datatype, so there is no need to bother about encodings. But I don't know how to do that in the context of Entity Framework
• https://stackoverflow.com/a/385756/1175496
• https://stackoverflow.com/a/1564803/1175496
  • If I change XML declaration to use encoding="utf-16" as these answers suggests, EntityFramework can saveChanges() with no errors, but I want to avoid (if possible):
    • Changing encodings
    • Stripping the declaration (even though I understand SQL Server doesn't store the declaration anyway)

Any ideas?