FE1 has a 
before the topmost note of the chord. This striking mistake was corrected in FE2. According to us, the error could have been caused by both staves being graphically similar in this place – the crotchet in the top voice on the 3rd space and a minim (-s) in the bottom one (the change of the rhythmic value of the topmost note must have been introduced later). In such a situation the flat would be a repetition of the sign written – unnecessarily – before e
on the bottom stave.
Compare the passage in the sources »
category imprint: Differences between sources
issues: Errors in FE, FE revisions
notation: Pitch