your array only allows for x values between 0 to 5
and y values between 0 and 1
and z values between 0 to 5
you have height and depth values reversed.
also, you have 8 columns and 8 rows (not 6, so your array should be 8 x 8 x 2).
when you calculate simplified X and Y you subtract 1, so you get values from -1 to 6
(you want 0 to 7, so don't subtract 1).
and don't save the LevelEditor array to local storage inside the loop, do it once after the loops finishes.
EDIT: I took another look and thought maybe you only want to save the middle 6 x 6 grid. The Save function selects all the Snow objects, and they are 8 x 8, so I guess their "Started" boolean should be set to true if they are not meant to be saved. If only the middle 6x6 tiles are to be saved then subtracting 1 would be correct.