This typically happens due to a cached file conflict or missing system prerequisites.
Using the FM 23 Editor is relatively straightforward. Here are the steps to get started:
Released by Sports Interactive (SI) via Steam, this editor allows you to edit the database before starting a save. You can change player attributes, club finances, league rules, and even add new nations.
: Purchase it through your respective store (Steam, Epic, or Microsoft) or via the "Downloads" section in the FM23 main menu.