NLog Target Extension

NLogのTargetをIsolatedStorageFileにしたくて調べていたのだが、中々上手く行かん。 他のアセンブリからターゲットクラスを呼び出す時点でエラーが出てしまう。

NLog.config

<?xml version="1.0" encoding="utf-8" ?>
<nlog>
    <extensions>
        <add assembly="Mandarine"/>
    </extensions>
    <targets>
        <target name="target1" type="IsolatedStorage" layout="${longdate} ${callsite} ${level} ${message}"/>
    </targets>
    <rules>
        <logger name="*" minlevel="Debug" writeTo="target1" />
    </rules>
</nlog>

IsolatedStorageTarget.cs

    [Target("IsolatedStorage")]
    public class IsolatedStorageTarget : TargetWithLayout 
	{
        public IsolatedStorageTarget() 
            : base()
        {
            
        }
        protected override void Write(LogEventInfo logEvent)
        {
            if (!System.ComponentModel.DesignerProperties.IsInDesignTool)
            {
                using (IsolatedStorageFile store =
                        IsolatedStorageFile.GetUserStoreForApplication())
                {
                    using (Stream stream =
                        new IsolatedStorageFileStream("Mandarine.log"
                            , FileMode.Append, FileAccess.Write, store))
                    {
                        var writer = new StreamWriter(stream);
                        writer.WriteLine(this.Layout.Render(logEvent));
                    }
                }
            }
        }
    }

うーむ。 また調べ物の時間だ。

NLog.NLogConfigurationException はハンドルされませんでした。
  Message=Exception occurred when loading configuration from NLog.config
  StackTrace:
       at NLog.Config.XmlLoggingConfiguration.Initialize(XmlReader reader, String fileName, Boolean ignoreErrors)
       at NLog.Config.XmlLoggingConfiguration..ctor(String fileName)
       at NLog.LogFactory.get_Configuration()
       at NLog.LogFactory.GetLogger(LoggerCacheKey cacheKey)
       at NLog.LogFactory.GetLogger(String name)
       at NLog.LogManager.GetCurrentClassLogger()
       :