diff --git a/__init__.py b/__init__.py
index f7209b1..72d24ea 100644
--- a/__init__.py
+++ b/__init__.py
@@ -1,2 +1,22 @@
+import logging
+import traceback
+from odoo.exceptions import UserError
+
+_logger = logging.getLogger(__name__)
+
+# Diagnostic monkey-patch to find where the UserError is coming from
+original_init = UserError.__init__
+
+def diagnostic_init(self, *args, **kwargs):
+    message = args[0] if args else ""
+    if "linked to an expense report" in str(message):
+        with open("/tmp/odoo_lock_traceback.txt", "w") as f:
+            f.write("LOCKED ERROR CAUGHT!\n")
+            f.write(f"Message: {message}\n")
+            f.write("TRACEBACK:\n")
+            traceback.print_stack(file=f)
+    return original_init(self, *args, **kwargs)
+
+UserError.__init__ = diagnostic_init
+
 from . import models
-from . import controllers