When i try to run Big Dig it get to the mojang screen then crashes pls help me fix it!!!!

[PLZ HELP ME!!!!!!!!!!!]

[Thoran]

Open the Technic Launcher, click the gear button next to the BigDig icon (its the screen you can change your version in) and click on Reset Pack. This will delete everything in the BigDig folder and force a new download for the files.

[shaaaa]

and if this doesnt work, delete manually the big dig folder (backup your saves before doing that)