diff --git a/Tests/FrameworkTests/OverwatchTranscriptTests/TranscriptTests.cs b/Tests/FrameworkTests/OverwatchTranscriptTests/TranscriptTests.cs
index c5b81ba..255ea17 100644
--- a/Tests/FrameworkTests/OverwatchTranscriptTests/TranscriptTests.cs
+++ b/Tests/FrameworkTests/OverwatchTranscriptTests/TranscriptTests.cs
@@ -117,10 +117,10 @@ namespace FrameworkTests.OverwatchTranscriptTests
             var e = events.SingleOrDefault(e => e.Moment.Utc == utc && e.Payload.EventData == data);
             if (e == null) Assert.Fail("Event not found");
 
-            Assert.That(e.Moment.Utc, Is.EqualTo(utc));
-            Assert.That(e.Moment.Duration, Is.EqualTo(duration));
-            Assert.That(e.Moment.Index, Is.EqualTo(index));
-            Assert.That(e.Payload.EventData, Is.EqualTo(data));
+            Assert.That(e!.Moment.Utc, Is.EqualTo(utc));
+            Assert.That(e!.Moment.Duration, Is.EqualTo(duration));
+            Assert.That(e!.Moment.Index, Is.EqualTo(index));
+            Assert.That(e!.Payload.EventData, Is.EqualTo(data));
         }
 
         private void AssertFileContent()
diff --git a/Tools/TranscriptAnalysis/Receivers/BaseReceiver.cs b/Tools/TranscriptAnalysis/Receivers/BaseReceiver.cs
index 17e02d7..8ab6a61 100644
--- a/Tools/TranscriptAnalysis/Receivers/BaseReceiver.cs
+++ b/Tools/TranscriptAnalysis/Receivers/BaseReceiver.cs
@@ -19,18 +19,19 @@ namespace TranscriptAnalysis.Receivers
             Header = header;
         }
 
-        protected string GetPeerId(int nodeIndex)
+        protected string? GetPeerId(int nodeIndex)
         {
-            return GetIdentity(nodeIndex).PeerId;
+            return GetIdentity(nodeIndex)?.PeerId;
         }
 
-        protected string GetName(int nodeIndex)
+        protected string? GetName(int nodeIndex)
         {
-            return GetIdentity(nodeIndex).Name;
+            return GetIdentity(nodeIndex)?.Name;
         }
 
-        protected CodexNodeIdentity GetIdentity(int nodeIndex)
+        protected CodexNodeIdentity? GetIdentity(int nodeIndex)
         {
+            if (nodeIndex < 0) return null;
             return Header.Nodes[nodeIndex];
         }
 
diff --git a/Tools/TranscriptAnalysis/Receivers/LogReplaceReceiver.cs b/Tools/TranscriptAnalysis/Receivers/LogReplaceReceiver.cs
index caddc60..d4963ee 100644
--- a/Tools/TranscriptAnalysis/Receivers/LogReplaceReceiver.cs
+++ b/Tools/TranscriptAnalysis/Receivers/LogReplaceReceiver.cs
@@ -14,6 +14,8 @@ namespace TranscriptAnalysis.Receivers
         {
             var peerId = GetPeerId(@event.Payload.NodeIdentity);
             var name = GetName(@event.Payload.NodeIdentity);
+            if (peerId == null) return;
+            if (name == null) return;
 
             if (!seen.Contains(peerId))
             {
diff --git a/Tools/TranscriptAnalysis/Receivers/NodesDegree.cs b/Tools/TranscriptAnalysis/Receivers/NodesDegree.cs
index 1677fdf..298d8d1 100644
--- a/Tools/TranscriptAnalysis/Receivers/NodesDegree.cs
+++ b/Tools/TranscriptAnalysis/Receivers/NodesDegree.cs
@@ -54,6 +54,7 @@ namespace TranscriptAnalysis.Receivers
             if (@event.Payload.DialSuccessful != null)
             {
                 var peerId = GetPeerId(@event.Payload.NodeIdentity);
+                if (peerId == null) return;
                 AddDial(peerId, @event.Payload.DialSuccessful.TargetPeerId);
             }
         }