Chances are your purchase(s) were still in transit when you attempted to uncompress. It is VERY important to allow the download to finish before attempting to view, open or otherwise work with the file. The browser download progress bar should disappear fully.

Note: The presence of a file icon doesn't always mean a transfer is complete- only that one has started.

Mac Users: Always decompress your purchase by double-clicking the archive in OS-10. This uses Apple's native decompression engine instead of third-party software such as StuffIt. We do not recommend using StuffIt as this may cause issues during decompression.