Complex sentence: The edition was prepared from 1825 to 1831, but difficulties with the censure will slow the publishing of the volumes, especially after the book has been put in the list of Index Librorum Prohibitorum in 1834.
Split into simpler sentences: The edition was prepared from 1825 to 1831, but difficulties with the censure will slow the publishing of the volumes. Effectuée entre 1825 et 1831, des difficultés avec la censure ralentiront la parution de ses volumes, especially after the book has been put in the list of Index Librorum Prohibitorum in 1834.