FM27 Editors
The official 2D-engine deep dive mentions an in-game editor among the deeper-world upgrades. That is the editor inside a running save: change a player or a club while you play, under whatever limits the mode has. I am not listing those limits, because the dive is not a manual and I have not opened the screen.
The pre-game editor is the official tool that edits the database before you start. FM Scout documents it for FM26. A Sports Interactive forum thread asks whether the FM27 pre-game editor is available during the free preview. A question is not a release. I will not tell you to download the FM26 editor and point it at FM27.
Live Editor 27 is a third-party tool with its own FM Scout page. Genie Scout 27 is confirmed on a separate FM Scout post as the scouting database people use outside the game. They do different jobs. Live Editor writes into a save. Genie Scout reads a database so you can plan. Neither is published by Sports Interactive.
Use them only on a copy of the save. The preview save is supposed to carry into the paid game, which means a broken edit now is a broken career in November. The author's page is the compatibility line. This page is the map of which tool is which.
Is there an official editor?
An in-game editor is in the official feature notes. A pre-game editor build for FM27 was not confirmed on 30 October.
What is Genie Scout 27?
A third-party scouting database. FM Scout says the FM27 edition is confirmed.
What is Live Editor?
A third-party tool for editing a running save. It is not the official in-game editor.