diff --git a/src/Microsoft.Extensions.Logging.Abstractions/Internal/FormattedLogValues.cs b/src/Microsoft.Extensions.Logging.Abstractions/Internal/FormattedLogValues.cs
index e65b7f7f..518759de 100644
--- a/src/Microsoft.Extensions.Logging.Abstractions/Internal/FormattedLogValues.cs
+++ b/src/Microsoft.Extensions.Logging.Abstractions/Internal/FormattedLogValues.cs
@@ -9,11 +9,12 @@
 namespace Microsoft.Extensions.Logging.Internal
 {
     /// <summary>
-    /// LogValues to enable formatting options supported by <see cref="M:string.Format"/>. 
+    /// LogValues to enable formatting options supported by <see cref="M:string.Format"/>.
     /// This also enables using {NamedformatItem} in the format string.
     /// </summary>
     public class FormattedLogValues : IReadOnlyList<KeyValuePair<string, object>>
     {
+        private const string NullFormat = "[null]";
         private static ConcurrentDictionary<string, LogValuesFormatter> _formatters = new ConcurrentDictionary<string, LogValuesFormatter>();
         private readonly LogValuesFormatter _formatter;
         private readonly object[] _values;
@@ -21,17 +22,12 @@ public class FormattedLogValues : IReadOnlyList<KeyValuePair<string, object>>
 
         public FormattedLogValues(string format, params object[] values)
         {
-            if (format == null)
-            {
-                throw new ArgumentNullException(nameof(format));
-            }
-
-            if (values.Length != 0)
+            if (values?.Length != 0 && format != null)
             {
                 _formatter = _formatters.GetOrAdd(format, f => new LogValuesFormatter(f));
             }
 
-            _originalMessage = format;
+            _originalMessage = format ?? NullFormat;
             _values = values;
         }
 
diff --git a/src/Microsoft.Extensions.Logging.Abstractions/Internal/LogValuesFormatter.cs b/src/Microsoft.Extensions.Logging.Abstractions/Internal/LogValuesFormatter.cs
index 22199d37..22611e54 100644
--- a/src/Microsoft.Extensions.Logging.Abstractions/Internal/LogValuesFormatter.cs
+++ b/src/Microsoft.Extensions.Logging.Abstractions/Internal/LogValuesFormatter.cs
@@ -15,12 +15,11 @@ namespace Microsoft.Extensions.Logging.Internal
     /// </summary>
     public class LogValuesFormatter
     {
+        private const string NullValue = "(null)";
+        private static readonly object[] EmptyArray = new object[0];
         private readonly string _format;
         private readonly List<string> _valueNames = new List<string>();
 
-        public string OriginalFormat { get; private set; }
-        public List<string> ValueNames => _valueNames;
-
         public LogValuesFormatter(string format)
         {
             OriginalFormat = format;
@@ -60,6 +59,9 @@ public LogValuesFormatter(string format)
             _format = sb.ToString();
         }
 
+        public string OriginalFormat { get; private set; }
+        public List<string> ValueNames => _valueNames;
+
         private static int FindBraceIndex(string format, char brace, int startIndex, int endIndex)
         {
             // Example: {{prefix{{{Argument}}}suffix}}.
@@ -124,6 +126,7 @@ public string Format(object[] values)
 
                     if (value == null)
                     {
+                        values[i] = NullValue;
                         continue;
                     }
 
@@ -137,12 +140,12 @@ public string Format(object[] values)
                     var enumerable = value as IEnumerable;
                     if (enumerable != null)
                     {
-                        values[i] = string.Join(", ", enumerable.Cast<object>().Where(obj => obj != null));
+                        values[i] = string.Join(", ", enumerable.Cast<object>().Select(o => o ?? NullValue));
                     }
                 }
             }
 
-            return string.Format(CultureInfo.InvariantCulture, _format, values);
+            return string.Format(CultureInfo.InvariantCulture, _format, values ?? EmptyArray);
         }
 
         public KeyValuePair<string, object> GetValue(object[] values, int index)
diff --git a/src/Microsoft.Extensions.Logging.Abstractions/LoggerExtensions.cs b/src/Microsoft.Extensions.Logging.Abstractions/LoggerExtensions.cs
index 97cec7ff..7dc09d16 100644
--- a/src/Microsoft.Extensions.Logging.Abstractions/LoggerExtensions.cs
+++ b/src/Microsoft.Extensions.Logging.Abstractions/LoggerExtensions.cs
@@ -352,11 +352,6 @@ public static IDisposable BeginScope(
                 throw new ArgumentNullException(nameof(logger));
             }
 
-            if (messageFormat == null)
-            {
-                throw new ArgumentNullException(nameof(messageFormat));
-            }
-
             return logger.BeginScope(new FormattedLogValues(messageFormat, args));
         }
 
diff --git a/src/Microsoft.Extensions.Logging.Debug/DebugLogger.cs b/src/Microsoft.Extensions.Logging.Debug/DebugLogger.cs
index a1657217..64d5d67b 100644
--- a/src/Microsoft.Extensions.Logging.Debug/DebugLogger.cs
+++ b/src/Microsoft.Extensions.Logging.Debug/DebugLogger.cs
@@ -58,7 +58,7 @@ public void Log<TState>(LogLevel logLevel, EventId eventId, TState state, Except
                 return;
             }
 
-            if(formatter == null)
+            if (formatter == null)
             {
                 throw new ArgumentNullException(nameof(formatter));
             }
diff --git a/test/Microsoft.Extensions.Logging.Test/ConsoleLoggerTest.cs b/test/Microsoft.Extensions.Logging.Test/ConsoleLoggerTest.cs
index 54d24199..1c6909db 100644
--- a/test/Microsoft.Extensions.Logging.Test/ConsoleLoggerTest.cs
+++ b/test/Microsoft.Extensions.Logging.Test/ConsoleLoggerTest.cs
@@ -15,6 +15,8 @@ namespace Microsoft.Extensions.Logging.Test
 {
     public class ConsoleLoggerTest
     {
+        private const int WritesPerMsg = 3;
+        private const int WritesPerError = 4;
         private readonly string _paddingString;
         private const string _loggerName = "test";
         private const string _state = "This is a test, and {curly braces} are just fine!";
@@ -54,16 +56,24 @@ private Tuple<ILoggerFactory, ConsoleSink> SetUpFactory(Func<string, LogLevel, b
         }
 
         [Fact]
-        public void ThrowsException_WhenNoMessageAndExceptionAreProvided()
+        public void LogsWhenMessageIsNotProvided()
         {
             // Arrange
             var t = SetUp(null);
             var logger = (ILogger)t.Item1;
             var sink = t.Item2;
+            var exception = new InvalidOperationException("Invalid value");
 
-            // Act & Assert
-            var exception = Assert.Throws<ArgumentNullException>(() => logger.LogCritical(eventId: 0, exception: null, message: null));
-            exception = Assert.Throws<ArgumentNullException>(() => logger.LogCritical(eventId: 0, message: null));
+            // Act
+            logger.LogCritical(eventId: 0, exception: null, message: null);
+            logger.LogCritical(eventId: 0, message: null);
+            logger.LogCritical(eventId: 0, message: null, exception: exception);
+
+            // Assert
+            Assert.Equal(10, sink.Writes.Count);
+            Assert.Equal(GetMessage("crit", 0, "[null]", null     ), GetMessage(sink.Writes.GetRange(0 * WritesPerMsg, WritesPerMsg)));
+            Assert.Equal(GetMessage("crit", 0, "[null]", null     ), GetMessage(sink.Writes.GetRange(1 * WritesPerMsg, WritesPerMsg)));
+            Assert.Equal(GetMessage("crit", 0, "[null]", exception), GetMessage(sink.Writes.GetRange(2 * WritesPerMsg, WritesPerError)));
         }
 
         [Fact]
@@ -74,7 +84,6 @@ public void DoesNotLog_NewLine_WhenNoExceptionIsProvided()
             var logger = (ILogger)t.Item1;
             var sink = t.Item2;
             var logMessage = "Route with name 'Default' was not found.";
-            var expectedMessage = _paddingString + logMessage + Environment.NewLine;
 
             // Act
             logger.LogCritical(logMessage);
@@ -84,10 +93,10 @@ public void DoesNotLog_NewLine_WhenNoExceptionIsProvided()
 
             // Assert
             Assert.Equal(12, sink.Writes.Count);
-            Assert.Equal(expectedMessage, sink.Writes[2].Message);
-            Assert.Equal(expectedMessage, sink.Writes[5].Message);
-            Assert.Equal(expectedMessage, sink.Writes[8].Message);
-            Assert.Equal(expectedMessage, sink.Writes[11].Message);
+            Assert.Equal(GetMessage("crit",  0, logMessage, null), GetMessage(sink.Writes.GetRange(0 * WritesPerMsg, WritesPerMsg)));
+            Assert.Equal(GetMessage("crit", 10, logMessage, null), GetMessage(sink.Writes.GetRange(1 * WritesPerMsg, WritesPerMsg)));
+            Assert.Equal(GetMessage("crit", 10, logMessage, null), GetMessage(sink.Writes.GetRange(2 * WritesPerMsg, WritesPerMsg)));
+            Assert.Equal(GetMessage("crit", 10, logMessage, null), GetMessage(sink.Writes.GetRange(3 * WritesPerMsg, WritesPerMsg)));
         }
 
         [Theory]
@@ -114,18 +123,6 @@ public void Writes_NewLine_WhenExceptionIsProvided(string message)
             Assert.Equal(expectedExceptionMessage, sink.Writes[3].Message);
         }
 
-        [Fact]
-        public void ThrowsException_WhenNoMessageIsProvided()
-        {
-            // Arrange
-            var t = SetUp(null);
-            var logger = (ILogger)t.Item1;
-            var exception = new InvalidOperationException("Invalid value");
-
-            // Act & Assert
-            Assert.Throws<ArgumentNullException>(() => logger.LogCritical(10, message: null, exception: exception));
-        }
-
         [Fact]
         public void ThrowsException_WhenNoFormatterIsProvided()
         {
@@ -445,12 +442,12 @@ public void WriteCore_LogsCorrectMessages()
 
             // Assert
             Assert.Equal(24, sink.Writes.Count);
-            Assert.Equal(GetMessage("crit", 0, ex), GetMessage(sink.Writes.GetRange(0, 4)));
-            Assert.Equal(GetMessage("fail", 0, ex), GetMessage(sink.Writes.GetRange(4, 4)));
-            Assert.Equal(GetMessage("warn", 0, ex), GetMessage(sink.Writes.GetRange(8, 4)));
-            Assert.Equal(GetMessage("info", 0, ex), GetMessage(sink.Writes.GetRange(12, 4)));
-            Assert.Equal(GetMessage("dbug", 0, ex), GetMessage(sink.Writes.GetRange(16, 4)));
-            Assert.Equal(GetMessage("trce", 0, ex), GetMessage(sink.Writes.GetRange(20, 4)));
+            Assert.Equal(GetMessage("crit", 0, ex), GetMessage(sink.Writes.GetRange(0 * WritesPerError, WritesPerError)));
+            Assert.Equal(GetMessage("fail", 0, ex), GetMessage(sink.Writes.GetRange(1 * WritesPerError, WritesPerError)));
+            Assert.Equal(GetMessage("warn", 0, ex), GetMessage(sink.Writes.GetRange(2 * WritesPerError, WritesPerError)));
+            Assert.Equal(GetMessage("info", 0, ex), GetMessage(sink.Writes.GetRange(3 * WritesPerError, WritesPerError)));
+            Assert.Equal(GetMessage("dbug", 0, ex), GetMessage(sink.Writes.GetRange(4 * WritesPerError, WritesPerError)));
+            Assert.Equal(GetMessage("trce", 0, ex), GetMessage(sink.Writes.GetRange(5 * WritesPerError, WritesPerError)));
         }
 
         [Fact]
@@ -518,7 +515,7 @@ public void WritingScopes_LogsExpectedMessage()
             var sink = t.Item2;
             var expectedMessage =
                 _paddingString
-                + $"=> RequestId: 100"
+                + "=> RequestId: 100"
                 + Environment.NewLine;
 
             // Act
@@ -536,6 +533,34 @@ public void WritingScopes_LogsExpectedMessage()
             Assert.Equal(TestConsole.DefaultForegroundColor, write.ForegroundColor);
         }
 
+        [Fact]
+        public void WritingNestedScope_LogsNullScopeName()
+        {
+            // Arrange
+            var t = SetUp(filter: null, includeScopes: true);
+            var logger = t.Item1;
+            var sink = t.Item2;
+            var expectedMessage =
+                _paddingString
+                + "=> [null] => Request matched action: (null)"
+                + Environment.NewLine;
+
+            // Act
+            using (logger.BeginScope(null))
+            {
+                using (logger.BeginScope("Request matched action: {ActionName}", new object[] { null }))
+                {
+                    logger.Log(LogLevel.Information, 0, _state, null, _defaultFormatter);
+                }
+            }
+
+            // Assert
+            Assert.Equal(4, sink.Writes.Count);
+            // scope
+            var write = sink.Writes[2];
+            Assert.Equal(expectedMessage, write.Message);
+        }
+
         [Fact]
         public void WritingNestedScopes_LogsExpectedMessage()
         {
@@ -545,7 +570,7 @@ public void WritingNestedScopes_LogsExpectedMessage()
             var sink = t.Item2;
             var expectedMessage =
                 _paddingString
-                + $"=> RequestId: 100 => Request matched action: Index"
+                + "=> RequestId: 100 => Request matched action: Index"
                 + Environment.NewLine;
 
             // Act
@@ -575,11 +600,11 @@ public void WritingMultipleScopes_LogsExpectedMessage()
             var sink = t.Item2;
             var expectedMessage1 =
                 _paddingString
-                + $"=> RequestId: 100 => Request matched action: Index"
+                + "=> RequestId: 100 => Request matched action: Index"
                 + Environment.NewLine;
             var expectedMessage2 =
                 _paddingString
-                + $"=> RequestId: 100 => Created product: Car"
+                + "=> RequestId: 100 => Created product: Car"
                 + Environment.NewLine;
 
             // Act
@@ -786,12 +811,12 @@ public void WriteCore_MessageWithNullException()
 
             // Assert
             Assert.Equal(18, sink.Writes.Count);
-            Assert.Equal(GetMessage("crit", 0, ex), GetMessage(sink.Writes.GetRange(0, 3)));
-            Assert.Equal(GetMessage("fail", 0, ex), GetMessage(sink.Writes.GetRange(3, 3)));
-            Assert.Equal(GetMessage("warn", 0, ex), GetMessage(sink.Writes.GetRange(6, 3)));
-            Assert.Equal(GetMessage("info", 0, ex), GetMessage(sink.Writes.GetRange(9, 3)));
-            Assert.Equal(GetMessage("dbug", 0, ex), GetMessage(sink.Writes.GetRange(12, 3)));
-            Assert.Equal(GetMessage("trce", 0, ex), GetMessage(sink.Writes.GetRange(15, 3)));
+            Assert.Equal(GetMessage("crit", 0, ex), GetMessage(sink.Writes.GetRange(0 * WritesPerMsg, WritesPerMsg)));
+            Assert.Equal(GetMessage("fail", 0, ex), GetMessage(sink.Writes.GetRange(1 * WritesPerMsg, WritesPerMsg)));
+            Assert.Equal(GetMessage("warn", 0, ex), GetMessage(sink.Writes.GetRange(2 * WritesPerMsg, WritesPerMsg)));
+            Assert.Equal(GetMessage("info", 0, ex), GetMessage(sink.Writes.GetRange(3 * WritesPerMsg, WritesPerMsg)));
+            Assert.Equal(GetMessage("dbug", 0, ex), GetMessage(sink.Writes.GetRange(4 * WritesPerMsg, WritesPerMsg)));
+            Assert.Equal(GetMessage("trce", 0, ex), GetMessage(sink.Writes.GetRange(5 * WritesPerMsg, WritesPerMsg)));
         }
 
         [Fact]
@@ -817,6 +842,9 @@ public void WriteCore_NullMessageWithNullException()
         }
 
         private string GetMessage(string logLevelString, int eventId, Exception exception)
+            => GetMessage(logLevelString, eventId, _state, exception);
+
+        private string GetMessage<TState>(string logLevelString, int eventId, TState state, Exception exception)
         {
             var loglevelStringWithPadding = $"{logLevelString}: ";
 
@@ -825,7 +853,7 @@ private string GetMessage(string logLevelString, int eventId, Exception exceptio
                 + $"{_loggerName}[{eventId}]"
                 + Environment.NewLine
                 + _paddingString
-                + ReplaceMessageNewLinesWithPadding(_state.ToString())
+                + ReplaceMessageNewLinesWithPadding(state?.ToString())
                 + Environment.NewLine
                 + ( exception != null
                     ? exception.ToString() + Environment.NewLine
diff --git a/test/Microsoft.Extensions.Logging.Test/FormattedLogValuesTest.cs b/test/Microsoft.Extensions.Logging.Test/FormattedLogValuesTest.cs
index f5812520..d59fd74e 100644
--- a/test/Microsoft.Extensions.Logging.Test/FormattedLogValuesTest.cs
+++ b/test/Microsoft.Extensions.Logging.Test/FormattedLogValuesTest.cs
@@ -11,6 +11,7 @@ namespace Microsoft.Extensions.Logging.Test
     public class FormattedLogValuesTest
     {
         [Theory]
+        [InlineData("", "", null)]
         [InlineData("", "", new object[] { })]
         [InlineData("arg1 arg2", "{0} {1}", new object[] { "arg1", "arg2" })]
         [InlineData("arg1 arg2", "{Start} {End}", new object[] { "arg1", "arg2" })]
@@ -25,6 +26,26 @@ public void LogValues_With_Basic_Types(string expected, string format, object[]
             Assert.Equal(format, logValues.First(v => v.Key == "{OriginalFormat}").Value);
         }
 
+        [Theory]
+        [InlineData("[null]", null, null)]
+        [InlineData("[null]", null, new object[] { })]
+        [InlineData("[null]", null, new object[] { null })]
+        [InlineData("[null]", null, new object[] { 1 })]
+        public void Log_NullFormat(string expected, string format, object[] args)
+        {
+            var logValues = new FormattedLogValues(format, args);
+            Assert.Equal(expected, logValues.ToString());
+        }
+
+        [Theory]
+        [InlineData("(null), (null) : (null)", "{0} : {1}", new object[] { new object[] { null, null }, null })]
+        [InlineData("(null)", "{0}", new object[] { null })]
+        public void LogValues_WithNulls(string expected, string format, object[] args)
+        {
+            var logValues = new FormattedLogValues(format, args);
+            Assert.Equal(expected, logValues.ToString());
+        }
+
         [Theory]
         [InlineData("1 2015", "{Year,6:d yyyy}")]
         [InlineData("1:01:2015 AM,:        01", "{Year,-10:d:MM:yyyy tt},:{second,10:ss}")]
@@ -83,7 +104,7 @@ public static TheoryData<string, object[], string> FormatsEnumerableValuesData
                     {
                         "The view '{ViewName}' was not found. Searched locations: {SearchedLocations}",
                         new object[] { "Index", null },
-                        "The view 'Index' was not found. Searched locations: "
+                        "The view 'Index' was not found. Searched locations: (null)"
                     },
                     // empty enumerable
                     {
@@ -101,13 +122,13 @@ public static TheoryData<string, object[], string> FormatsEnumerableValuesData
                     {
                         "The view '{ViewName}' was not found. Searched locations: {SearchedLocations}",
                         new object[] { "Index", new string[] { null } },
-                        "The view 'Index' was not found. Searched locations: "
+                        "The view 'Index' was not found. Searched locations: (null)"
                     },
                     // null value item in enumerable
                     {
                         "The view '{ViewName}' was not found. Searched locations: {SearchedLocations}",
                         new object[] { "Index", new string[] { null, "Views/Home/Index.cshtml" } },
-                        "The view 'Index' was not found. Searched locations: Views/Home/Index.cshtml"
+                        "The view 'Index' was not found. Searched locations: (null), Views/Home/Index.cshtml"
                     },
                     // multi item enumerable
                     {
@@ -151,7 +172,7 @@ public static TheoryData<string, object[], string> FormatsEnumerableValuesData
                         "The view '{ViewName}' was not found. Searched locations: {SearchedLocations}",
                         new object[] { "Index", new Uri[][] { null, new[] { new Uri("http://def") } } },
                         "The view 'Index' was not found. Searched locations: " +
-                        "System.Uri[]"
+                        "(null), System.Uri[]"
                     },
                     // non-string sub-enumerables
                     {