On setting values for manifest URL following is seen

Exception traceback

Traceback (innermost last):

• Module Products.ERP5Type.patches.WSGIPublisher, line 265, in transaction_pubevents
  yield
• Module Products.ERP5Type.patches.WSGIPublisher, line 442, in publish_module
  response = _publish(request, new_mod_info)
• Module Products.ERP5Type.patches.WSGIPublisher, line 375, in publish
  bind=1)
• Module ZPublisher.mapply, line 77, in mapply
  if debug is not None: return debug(object,args,context)
• Module Products.ERP5Type.Timeout, line 120, in deadlined_call_object
  return call_object(object, args, request)
• Module ZPublisher.Publish, line 48, in call_object
  result=apply(object,args) # Type s<cr> to step into published object.
• Module Products.ERP5Type.patches.PythonScript, line 179, in __call__
  return self._orig_bindAndExec(args, kw, None)
• Module Shared.DC.Scripts.Bindings, line 359, in _bindAndExec
  return self._exec(bound_data, args, kw)
• Module Products.PythonScripts.PythonScript, line 344, in _exec
  result = f(*args, **kw)
• Module script, line 43, in Base_createAppConfigurationManifest
  <PythonScript at /erp5/Base_createAppConfigurationManifest used for /erp5/web_site_module/officejs_nice_editor/app>
  Line 43
  configuration_file_reference = getElementFromContent("configuration_manifest", router_content)
• Module script, line 9, in getElementFromContent
  <PythonScript at /erp5/Base_createAppConfigurationManifest used for /erp5/web_site_module/officejs_nice_editor/app>
  Line 9
  start = content.find(before) + len(before)

AttributeError: 'NoneType' object has no attribute 'find'