From 8bed4951353f17ce825e6eb26363af6afe78d181 Mon Sep 17 00:00:00 2001
From: Kitty Draper <kitty.draper@unity3d.com>
Date: Thu, 29 Jun 2023 14:38:42 -0500
Subject: [PATCH 1/3] fix: compile error with generic NetworkBehaviour
 singletons

---
 .../Editor/CodeGen/CodeGenHelpers.cs                        | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/com.unity.netcode.gameobjects/Editor/CodeGen/CodeGenHelpers.cs b/com.unity.netcode.gameobjects/Editor/CodeGen/CodeGenHelpers.cs
index 473e84f219..1bb3ab1b16 100644
--- a/com.unity.netcode.gameobjects/Editor/CodeGen/CodeGenHelpers.cs
+++ b/com.unity.netcode.gameobjects/Editor/CodeGen/CodeGenHelpers.cs
@@ -59,7 +59,7 @@ public static uint Hash(this MethodDefinition methodDefinition)
 
         public static bool IsSubclassOf(this TypeDefinition typeDefinition, string classTypeFullName)
         {
-            if (!typeDefinition.IsClass)
+            if (typeDefinition == null || !typeDefinition.IsClass)
             {
                 return false;
             }
@@ -154,6 +154,10 @@ public static MethodReference MakeGeneric(this MethodReference self, params Type
 
         public static bool IsSubclassOf(this TypeReference typeReference, TypeReference baseClass)
         {
+            if (typeReference == null)
+            {
+                return false;
+            }
             var type = typeReference.Resolve();
             if (type?.BaseType == null || type.BaseType.Name == nameof(Object))
             {

From ac2275f591991ced28d2b7dc607ca6173013f7aa Mon Sep 17 00:00:00 2001
From: Kitty Draper <kitty.draper@unity3d.com>
Date: Thu, 29 Jun 2023 14:41:27 -0500
Subject: [PATCH 2/3] changelog

---
 com.unity.netcode.gameobjects/CHANGELOG.md | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/com.unity.netcode.gameobjects/CHANGELOG.md b/com.unity.netcode.gameobjects/CHANGELOG.md
index 46cc459577..ee16567e6f 100644
--- a/com.unity.netcode.gameobjects/CHANGELOG.md
+++ b/com.unity.netcode.gameobjects/CHANGELOG.md
@@ -6,6 +6,12 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 
 Additional documentation and release notes are available at [Multiplayer Documentation](https://docs-multiplayer.unity3d.com).
 
+## [Unreleased]
+
+### Fixed
+
+- Fixed an ILPP compile error when creating a generic NetworkBehaviour singleton with a static T instance. (#2603)
+
 ## [1.5.1] - 2023-06-07
 
 ### Added

From 75aeaa37f5cd1d1e9300eeb0311ca3e13a230959 Mon Sep 17 00:00:00 2001
From: Kitty Draper <kitty.draper@unity3d.com>
Date: Fri, 30 Jun 2023 16:41:00 -0500
Subject: [PATCH 3/3] Added another fix for a similar issue.

---
 .../Editor/CodeGen/NetworkBehaviourILPP.cs                  | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/com.unity.netcode.gameobjects/Editor/CodeGen/NetworkBehaviourILPP.cs b/com.unity.netcode.gameobjects/Editor/CodeGen/NetworkBehaviourILPP.cs
index b7ad88ca88..84133fff0d 100644
--- a/com.unity.netcode.gameobjects/Editor/CodeGen/NetworkBehaviourILPP.cs
+++ b/com.unity.netcode.gameobjects/Editor/CodeGen/NetworkBehaviourILPP.cs
@@ -2225,6 +2225,12 @@ private void GenerateVariableInitialization(TypeDefinition type)
                     }
                     field = new FieldReference(fieldDefinition.Name, fieldDefinition.FieldType, genericType);
                 }
+
+                if (field.FieldType.Resolve() == null)
+                {
+                    continue;
+                }
+
                 if (!field.FieldType.IsArray && !field.FieldType.Resolve().IsArray && field.FieldType.IsSubclassOf(m_NetworkVariableBase_TypeRef))
                 {
                     // if({variable} == null) {