ummmm................ does anybody have an explanation for this:

so i downloaded this mod and i thought it would work like 2 many items did,just righr,right? well wrong!

i was geting bored because it wasn`t working right so i went creative and flew around all of a sudden i fond this structure and found a block made out of something other than sandstone in it,so i broke it and fell........ i fell into this weird little compartment no dugon or anything........... i soon found a random floating,i think about 3x3 sized islandwith a tree on it,.......IT WAS FLOATING!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!