Czuch: First you may try to download the file again. Please compare the file sizes, the one which is shown during the download, and the one of the file on your computer after the download has finished. If the size of the downloaded file is less than the predicted size, then the file wasn't downloaded completely and thus can't be opened. If this happens more than once you may try to create the zip file again. If this doesn't help as well then I don't know either... Probably Fencer could check whether the zip file on the server is OK?