Bart900

Hello technic community. I recently installed the most latest version of tekkit just tekkit with the picture of the guy on the moon; and I made a sp world today I see the new things that are out since I haven't played in a while. So I went about getting the stuff together to build a house so I mined some marble and then I believe the computer crashed. So I fired it up again and went to load my world the second time to only find out that it goes straight back to the pack selection screen. Any clue as to what happened? Thanks in advance.