There’s a syntax error in the display name for this soundpack in the soundpack.txt. In recent experimental versions, the way ./config/options.json is created uses ’ as a separator so attempting to load @'s soundpack into a game will cause a serious error in the game resulting in negative several billion player move speed. Dropping the apostrophes from the display name in cdda\data\sound\damalsksoundpack-0.2\soundpack.txt to
NAME: @s soundpack#Viewing name of the soundpack
VIEW: @s soundpack
fixes the loading error.