System.TypeInitializationException in Log4Net.

    public class Log4NetTest
    {

        public void TestRun()
        {
            log4net.Config.XmlConfigurator.Configure();
            var log = LogManager.GetLogger(typeof(Log4NetTest));
            log.Error("Worse");
            log.Info("Dont Kid");
        }
    }

    public class Log4NetTypeMock
    {
        public static readonly ILog log
            = LogManager.GetLogger(typeof(Log4NetTypeMock))
            ;

        public static readonly Log4NetTest log4Net;
    }

      [Test, Isolated]
        public void Test1()
        {
            Isolate.WhenCalled(() => Log4NetTypeMock.log)
            .ReturnRecursiveFake();
            Assert.AreEqual(2, 1 + 1);
        }
        [Test, Isolated]
        public void Test3()
        {
            Isolate.WhenCalled(() => Log4NetTypeMock.log4Net)
.ReturnRecursiveFake();

            Isolate.WhenCalled(() => Log4NetTypeMock.log)
.ReturnRecursiveFake();
            Assert.AreEqual(2, 1 + 1);
        }