diff --git a/addons/metadata/utils.py b/addons/metadata/utils.py
index ed3b662d8b0..aaacd0ae136 100644
--- a/addons/metadata/utils.py
+++ b/addons/metadata/utils.py
@@ -151,7 +151,7 @@ def transform_name_fields_item(data):
     if creators is not None:
         rows = creators['value']
         if isinstance(rows, str):
-            rows = json.loads(rows)
+            rows = json.loads(rows) if rows.strip() else []
             creators['value'] = rows
         if isinstance(rows, list) and _transform_creators_rows(rows):
             dirty = True
diff --git a/osf/migrations/0270_remove_metadata_access_rights.py b/osf/migrations/0270_remove_metadata_access_rights.py
new file mode 100644
index 00000000000..d202998c716
--- /dev/null
+++ b/osf/migrations/0270_remove_metadata_access_rights.py
@@ -0,0 +1,43 @@
+from django.db import migrations
+
+noop = migrations.RunPython.noop
+
+TARGET_SCHEMA_NAME = '公的資金による研究データのメタデータ登録'
+
+OBSOLETE_KEY = 'grdm-file:metadata-access-rights'
+
+
+def _transform_item(data):
+    if OBSOLETE_KEY in data:
+        data.pop(OBSOLETE_KEY, None)
+        return True
+    return False
+
+
+def _transform_entry(entry):
+    metadata = entry.get('metadata', {})
+    if OBSOLETE_KEY in metadata:
+        metadata.pop(OBSOLETE_KEY, None)
+        return True
+    return False
+
+
+def remove_metadata_access_rights(*args):
+    from addons.metadata.utils import FileMetadataMigrator
+    migrator = FileMetadataMigrator(
+        TARGET_SCHEMA_NAME,
+        _transform_item,
+        _transform_entry,
+    )
+    migrator.run()
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('osf', '0269_merge_20260525_0425'),
+    ]
+
+    operations = [
+        migrations.RunPython(remove_metadata_access_rights, noop),
+    ]