Thank you! This is now corrected for version 5c as follows: (changes/additions in blue)
Rnd 4: Ch 3 (counts as a dc), dc in next sc, 2 dc in next sc, *dc in next 2 sc, 2 dc in next sc. Rep from * around; join with sl st to top of ch-3. (48 dc)
Rnd 5: Ch 1, sc in same dc, fpdc (see Stiches) around each post of next 3 dc, [sc in each next 2 dc, fpdc around post of next dc] twice, sc in next dc, fpdc around post of next dc, *sc in next dc, fpdc around each post of next 3 dc, [sc in next 2 dc, fpdc around post of next dc] twice, sc in next dc, fpdc around post of next dc. Rep from * around; join with sl st to first sc. (24 sc, 24 fpdc)