Blender closes/crashes immediately after pressing 'P' to start Game Engine.

My 3D view consists of a plane, a cube and 4 wheels that I am using to make a simple car which I am applying 3 scripts to in order to make me able to drive it. However, every time I press ‘P’ to start the Game Engine, Blender will immediately close without giving me any error message.
The scripts consist of:

Necessary computer details:

  • i5 4670k CPU
  • 8GB RAM
  • GTX 65 Ti GPU (with up-to-date drivers)
  • Windows 8
  • Blender 2.73a (also tried 2.69)

Please help!

Hello! The bug (concerned bge.constraints only windows 8) has been fixed 2 days ago by Lordloki! Thanks to him! Try the last releases of Blender here: https://builder.blender.org/download/ or try with a 2.73a 32 bits version.