ItemStack JSON don't work with all chars and empty lines (lore).

[GotoFinal]

If you have empty line in lore, it will be changed to "" (visible in item lore). If you use "" then you get empty line. if you use """ then you get "Invalid Item" message. If you use " then you get "Invalid Item" message.

So parsing " is broken.

(Not tested how that works with Achievements and Statistics)

[glen3b]

Sounds like an issue with the conversion to JSON. Will look into it when I get a chance.