I kept getting this error message "we were unable to download necessary files after five attempts. You can try running the application again, but if it fails you may need to uninstall and reinstall". So I did as it said and uninstalled/reinstalled, only to have it go through the same thing (except it takes 10x longer to go through the five retries).
Played yesterday and everything was fine.
Rightclick the following links and save as in your Spiral Knights directory (overwrite existing files):
getdown.txt
digest.txt
Then find the file called version.txt in your installation directory and replace the contents with 20111116121219.
Then try launching the game to patch as normal.