So I had put down my goty copy for a while , started a new game and now I can't jump. The A key works for me to select items and works for other games but I can jump. If I load up old saved games they can't jump either.

Anyone know how to fix this?

I have removed old software off the xbox

The Y button is the default jump button if I remember correctly......are you sure you are pressing the right button? And are you over-encumbered?