So on Friday I uploaded a map called Legend of Hearthoen. Today I went to show it to my friend and it wasn't in my worlds. So I went to %appdata%/roming/.minecraft and the folder was there, however it contained a ##MCEDIT.TEMP## folder. I downloaded the version from the internet that I uploaded and it now works. What I want to know is, Was it the ##MCEDIT.TEMP## folder which caused this or did my world become corrupted.
The ##MCEDIT.TEMP## folder is created when anything in the world is edited with MCEdit. The presence of the folder shouldn't have caused an issue, so my guess is that somehow your world got corrupted. Either way, the ##MCEDIT.TEMP## folder isn't (or at least shouldn't be) an issue..
I think the problem is you might've put the folder at %appdata%/roaming/.minecraft... You must put the world folder at %appdata%/roaming/.minecraft/saves
##MCEDIT.TEMP## in map folder