If you are looking for the "proper" content to make this version work, users often need to:

If the game isn't saving, you might need to check the save file path, which is typically located in your Steam library folder or a specific CODEX appdata folder.

Copy the contents from the CODEX folder inside the downloaded files and paste them into the main game installation directory, replacing the original files.

The PC version includes some content that was originally DLC on the Wii U, such as the Nightmare zone.