My Map Is Broken

My map is GeorgeCraft 2 (263 MB) and the last time I uploaded it, the map won't work. Now it's just like a black hole. Please help, I know that the file size is not a problem because I have a bigger map that works just fine.

your map has really far (really really far!) away chunks (usually dued to comming back from nether/netherportals).
your map isn't black, its just totally zoomed out. zoom in, and you'll see the map.

if you want to improve zoom levels, make a backup (!), delete chunk-files with high numbers and upload again.