diff --git a/Editor/FixupPasses/FixupExpressionsMenuPass.cs b/Editor/FixupPasses/FixupExpressionsMenuPass.cs
index f4b549ee..4f36ec2b 100644
--- a/Editor/FixupPasses/FixupExpressionsMenuPass.cs
+++ b/Editor/FixupPasses/FixupExpressionsMenuPass.cs
@@ -19,6 +19,8 @@ internal class FixupExpressionsMenuPass
 
         internal static void FixupExpressionsMenu(BuildContext context)
         {
+            if (!context.AvatarDescriptor) return;
+
             context.AvatarDescriptor.customExpressions = true;
 
             var expressionsMenu = context.AvatarDescriptor.expressionsMenu;
diff --git a/Editor/MergeAnimatorProcessor.cs b/Editor/MergeAnimatorProcessor.cs
index 69fb0e28..5b25649c 100644
--- a/Editor/MergeAnimatorProcessor.cs
+++ b/Editor/MergeAnimatorProcessor.cs
@@ -65,6 +65,7 @@ internal void OnPreprocessAvatar(GameObject avatarGameObject, BuildContext conte
             mergeSessions.Clear();
 
             var descriptor = avatarGameObject.GetComponent<VRCAvatarDescriptor>();
+            if (!descriptor) return;
 
             if (descriptor.baseAnimationLayers != null) InitSessions(descriptor.baseAnimationLayers);
             if (descriptor.specialAnimationLayers != null) InitSessions(descriptor.specialAnimationLayers);
diff --git a/Editor/OptimizationPasses/PruneParametersPass.cs b/Editor/OptimizationPasses/PruneParametersPass.cs
index a38b3655..801fb3e9 100644
--- a/Editor/OptimizationPasses/PruneParametersPass.cs
+++ b/Editor/OptimizationPasses/PruneParametersPass.cs
@@ -9,6 +9,8 @@ internal class PruneParametersPass : Pass<PruneParametersPass>
     {
         protected override void Execute(ndmf.BuildContext context)
         {
+            if (!context.AvatarDescriptor) return;
+
             var expParams = context.AvatarDescriptor.expressionParameters;
             if (expParams != null && context.IsTemporaryAsset(expParams))
             {
diff --git a/Editor/RenameParametersHook.cs b/Editor/RenameParametersHook.cs
index 697633b7..c4ae0b75 100644
--- a/Editor/RenameParametersHook.cs
+++ b/Editor/RenameParametersHook.cs
@@ -183,6 +183,8 @@ private void SetExpressionParameters(GameObject avatarRoot, ImmutableDictionary<
                 .ToImmutableDictionary();
             
             var avatar = avatarRoot.GetComponent<VRCAvatarDescriptor>();
+            if (!avatar) return;
+
             var expParams = avatar.expressionParameters;
 
             if (expParams == null)