Problem Statement

MovieDB is an app that lets users explore movies, submit ratings, and share reviews. The custom lists feature lets users build personalised collections of movies and organise them according to their preferences. This feature is not working correctly on the backend, which prevents users from managing their lists effectively. Issue Summary Users are able to create custom lists, but they cannot add movies to those lists. As a result, the feature does not serve its intended purpose. The CustomListController endpoints for adding and removing movies return a generic Server error instead of updating the list. Steps to Reproduce Log in as a user and open Your Lists from the profile menu in the navbar. Create a new custom list — this succeeds and a listId is returned. Open any movie and try to add it to the list you just created. The movie is never added: the list stays empty and the API responds with an error. Expected API Behaviour POST /api/lists Creates a custom list owned by the authentica