My spacebar has no command

Put the summary of the bug you're having here
For some reason I can't jump, and when I go into controls, when I get to were the space control would be I crash. When I try to re-download minecraft nothing changes.

What I expected to happen was...: That I would be able to log on like normal.
Describe what you thought should happen here. I thought things would be normal.

What actually happened was...: I couldn't jump.
Describe what happened here I could not jump nor fly

Steps to Reproduce:
1. ...unknown
2. ...unknown
3. ...unknown