Error encountered

Internal error

Stack trace:

    Traceback (most recent call last):
  File "/usr/local/lib/taler-merchant-demos/venv/lib/python3.11/site-packages/flask/app.py", line 1484, in full_dispatch_request
    rv = self.dispatch_request()
         ^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/taler-merchant-demos/venv/lib/python3.11/site-packages/flask/app.py", line 1469, in dispatch_request
    return self.ensure_sync(self.view_functions[rule.endpoint])(**view_args)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/taler-merchant-demos/venv/lib/python3.11/site-packages/talermerchantdemos/blog/blog.py", line 366, in article
    order_resp = post_order(article_name, lang)
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/taler-merchant-demos/venv/lib/python3.11/site-packages/talermerchantdemos/blog/blog.py", line 309, in post_order
    summary = f"Essay: {article_info.title}"
                        ^^^^^^^^^^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'title'