Once upon a time I remember seeing info that said something about texture maps (specified within the shaders) that were moved (or changed, renamed) that Carrara couldn't find & therefore crashed. You may try & "import" the scene to a new assembl room project and not use the "open" command. Don't know if that will help. Have you tried to assign more ram to Carrara? The file may be too big to handle with the previous save. Carrara tends to "bloat" files with meshes in them.