[LYN-4527] Make sure the PrefabIntegrationManager is only created when prefabs are enabled, otherwise could result in crashes.

Code/Sandbox/Plugins/ComponentEntityEditorPlugin/SandboxIntegration.cpp

@@ -154,11 +154,23 @@ SandboxIntegrationManager::SandboxIntegrationManager()
 {
     // Required to receive events from the Cry Engine undo system
     GetIEditor()->GetUndoManager()->AddListener(this);
+
+    // Only create the PrefabIntegrationManager if prefabs are enabled
+    bool prefabSystemEnabled = false;
+    AzFramework::ApplicationRequests::Bus::BroadcastResult(
+        prefabSystemEnabled, &AzFramework::ApplicationRequests::IsPrefabSystemEnabled);
+    if (prefabSystemEnabled)
+    {
+        m_prefabIntegrationManager = aznew AzToolsFramework::Prefab::PrefabIntegrationManager();
+    }
 }
 
 SandboxIntegrationManager::~SandboxIntegrationManager()
 {
     GetIEditor()->GetUndoManager()->RemoveListener(this);
+
+    delete m_prefabIntegrationManager;
+    m_prefabIntegrationManager = nullptr;
 }
 
 void SandboxIntegrationManager::Setup()
@@ -187,11 +199,16 @@ void SandboxIntegrationManager::Setup()
     AZ_Assert((m_editorEntityUiInterface != nullptr),
         "SandboxIntegrationManager requires a EditorEntityUiInterface instance to be present on Setup().");
 
+    bool prefabSystemEnabled = false;
+    AzFramework::ApplicationRequests::Bus::BroadcastResult(
+        prefabSystemEnabled, &AzFramework::ApplicationRequests::IsPrefabSystemEnabled);
+    if (prefabSystemEnabled)
+    {
         m_prefabIntegrationInterface = AZ::Interface<AzToolsFramework::Prefab::PrefabIntegrationInterface>::Get();
-
         AZ_Assert(
             (m_prefabIntegrationInterface != nullptr),
             "SandboxIntegrationManager requires a PrefabIntegrationInterface instance to be present on Setup().");
+    }
 
     m_editorEntityAPI = AZ::Interface<AzToolsFramework::EditorEntityAPI>::Get();
     AZ_Assert(m_editorEntityAPI, "SandboxIntegrationManager requires an EditorEntityAPI instance to be present on Setup().");

Code/Sandbox/Plugins/ComponentEntityEditorPlugin/SandboxIntegration.h

@@ -305,7 +305,7 @@ private:
 
     bool m_debugDisplayBusImplementationActive = false;
 
-    AzToolsFramework::Prefab::PrefabIntegrationManager m_prefabIntegrationManager;
+    AzToolsFramework::Prefab::PrefabIntegrationManager* m_prefabIntegrationManager = nullptr;
 
     AzToolsFramework::EditorEntityUiInterface* m_editorEntityUiInterface = nullptr;
     AzToolsFramework::Prefab::PrefabIntegrationInterface* m_prefabIntegrationInterface = nullptr;