Its a sign your humidity was too low. If your using a tank you need to help by misting the tank daily. Also covering the top of the screen with aluminum foil and tape it down. This will hold in heat and humidity. If your using a heat lamp switch to a under tank heater and that will help as well.
To help with the shed do this.
Get a pillow case wet with warm water
Toss in the snake and tie it off.
Then put the pillow case on the warm side of the cage for 45 mins. This will cause the snake to move around looking for a way out and rub off the remaining skin.