Rd1212

I have made a new world and opened it with mcedit then i went back into attack of the b team and it was the same world i made with the same name, may you please be a bit more specific with how to do this thanks?

So what can i do to fix this?

I was playing attack of the b-team and i was playing with the statues mod and i crafted a showcase and placed it next to my item system from project red transportation then i broke it cause i wanted to move it so i did then i went back to use my item system and it wasnt working so i moved my item system 1 block over and i was placing blocks to cover up the piping next to the routed interface pipe and it crashed my game so i loaded it up the next day and started to rebuild it and it crashed again, so i loaded attack of the b-team up again and went into single player and my world was gone, so i went into my technic launcher folder (im using mac) and went to attack of the b-team and then into saves, my world was still there but the was 3 other folders called mapwriter_mp_worlds the next one was mapwriter_sp_worlds and the final one was NEI can someone please help me i worked very hard with that world. :'(

I am on a mac can anyone please help me how to change this??!?!?!??!