Usually invalid download state means that the torrent ran into an error the last time you had your torrent client open, usually that there are file(s) supposedly missing. Data is Invalid is usually a sign that when it completed a file, it did not remove the .!ut from the end of the file name, so it thinks the file is not there, as it was reported as 100% downloaded, but the file was not renamed to remove the partial status from the end of the file name.
In both cases, Force Re-Check, then starting the torrent will fix this.