ValidateInput（false）和AllowHtml属性仍然导致'检测到潜在危险的Request.Form值'

I have on my model:

我有我的模特:

public class EmailTemplateModel
{
    public int EmailTemplateId { get; set; }

    [Required]
    public string Name { get; set; }
    [Required]
    public string Subject { get; set; }

    [AllowHtml]
    [Required]        
    public string Content { get; set; }
}
public class Em