Invoke download and copy/paste to server and this works fine.
A tilemap.json = c2tilemap":true,"width":300,"height":400,"d....
(this one loads)
Upload via an ajax POST to server and this is does not work.
A tilemap.json = {"c3":true,"ivs":{"347965742015898":0,"350344174.....
(this does not load and tosses a parse error)
Any clue?