DireWolf20 1.6.4 Crash- I can't select my world!

[ikik32]

I recently crashed while playing the DireWolf20 pack in my single player world. I thought it was nothing to be worried about because I do occasionally crash when playing these large modpacks. However, when I loaded the game back up my world was not available to be selected. There were no worlds to choose from, as if it was my first time playing. When I look in the saves folder, my world is still there. I have no idea what is happening and any help would be much appreciated! (P.S. I play on mac.)

Here is the crash log:

 

[ikik32]

I think it has something to do with the level.dat file missing. I created a new world and compared its files to my world. The only difference is the level.dat file isn't there.

 

[ikik32]

thanks for the help!