I click the 'Start' button and it loads about half way and it comes up with an error page.

Put the summary of the bug you're having here

What I expected to happen was...
The game to start

What actually happened was...:
It didn't
Steps to Reproduce:
1. click on the play button
2. it crashes

here is the code thing that it gave me:

Unable to save download. fil_ph.lang
Name: fil_ph.lang
URL: http://resources.download.minecraft.net/cd/cdbdf93c0dbb749f036123e112f05377cc618603
Error details: Attempting to move successful download to C:/Users\capa2\AppData\Roaming\.minecraft\assets\objects\cd/cdbdf93c0dbb749f036123e112f05377cc618603 The process cannot access the file because it is being used by another process
Filename on disk: 223a-38db-0feb-24f4
Path: C:\Users\capa2\AppData\Local\Temp\223a-38db-0feb-24f4
Exists: false