campaign won't play

I know this is the HOTS forum, but WIL is pretty inactive today so .........

I finally got my brother to try out SCII. He is playing the campaign. However when he got to a certain stage it says that the version of SCII is not available to play. I take it its do to blizzards constant updates . But the game automatically searches for new patches when it starts up. So I should have the latest right ? Anyone else having this problem ?

Update: Problem solved!
(I'm leaving this up in case somebody else runs into this problem)

I found a solution on another forum. I located a file and moved it witch made SC scan and repair all files that are damaged. The file is located in:

/program files/StarCraft II/Battle.net/

the file name in that directory is called:

"Battle.net.MPQ"

The forum suggested deleting the file but I just moved it in case that wasn't the problem or it caused more problems.
After launching the game SC started a download of about 200mb, witch it must have found other files that needed repair or replacement because the original file was only about 50mb, my brother then was able to resume playing the campaign.

Note: Some minor things got changed, I noticed the game speed was reset don't know if anything else was affected.