The following is a list of all known note errors in all printings of 24 Preludes and Fugues. If you purchased your book after the given date, the error does not exist in your copy.
(February 8, 2016) Prelude in F Minor — m.84 soprano trill on A should be a quarter note.
(February 3, 2016) Fugue in E Major — m.15 alto C-Sharp should be A-Sharp.
(January 7, 2016) Fugue in G-Sharp Minor — m.21
(August 16, 2015) Fugue in C Major — m.24 soprano A 16th should be G-A 32nds.
(August 16, 2015) Fugue in C Major — m.29 soprano C should be a D.
(March 29, 2015) Prelude in D Major — m.55 in the treble clef the G needs a sharp.