From 7001a1b790d2b367852df232a258cf131a0f5535 Mon Sep 17 00:00:00 2001
From: Sarthak Kapoor <sarthakkapoor@hotmail.com>
Date: Thu, 2 Apr 2026 16:40:12 +0200
Subject: [PATCH] Check for existence of substrate

---
 src/nomad_material_processing/general.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/nomad_material_processing/general.py b/src/nomad_material_processing/general.py
index 645444a..e4e0f02 100644
--- a/src/nomad_material_processing/general.py
+++ b/src/nomad_material_processing/general.py
@@ -968,7 +968,7 @@ def normalize(self, archive: 'EntryArchive', logger: 'BoundLogger') -> None:
             logger (BoundLogger): A structlog logger.
         """
         self.components = []
-        if self.substrate.reference:
+        if self.substrate and self.substrate.reference:
             self.components.append(
                 SystemComponent(
                     name=self.substrate.name, system=self.substrate.reference