I've never had any problems with this Editor for Fallout 1, but place and run it from the Fallout 1 folder, that way it can find your save games - and yes it needs a save game file to work. As for the latest patches for Fallout 1 and their compatibility with the "Falche Editor", I don't know.
IMO these type of editors kill the games enjoyment, unless your trying to fix a crippled limb...