[please help] not saving worlds

[Jimbo]

I have forge and some mods installed. when i am done playing and hit save and quit to title it will say "shutting down internal server...." and then minecraft will close without saving my progress in the world i was playing. please help?

[loordgek]

shutting down internal server= saving

 

if you enter your safe where do you spawn??

and which ar u useing