Here are updates on two of the walks included in Spanish Trails Book One, Picos de Europa. (These updates are included in the latest print run.)

Walk 26. Sedo de Mabro. In the very final paragraph on page 130, please note that as you descend the valley you will need to cross the stream several times. It is often dry, but after heavy rain or snow melt this might present a degree of difficulty.
Walk 18. Fuente Dé to Vega de Llordes.  With reference to the route“Via the cable car and Canal San Luis” :
I wrote up this walk in 2017. I have been informed that during 2018 this route has been clearly marked with red paint. However, I suggest that you follow the directions in the book and use the red marks for confirmation.