They told me that WinRar or WinZip say that the file is corrupted or damaged.
I checked my files and I had no problem at all to download and extract the files. Everything works well on my PC.
So I don't really know how to deal with that but .... One of my friend who cannot extracted my files tried to do it with another version of WinRar than the one I use, or the one she usally use (older or most recent, 32 Bit or 64 Bit) and look like she finally succed to extract them and solved the problem like that. Maybe 32 Bit and 64 Bit versions have some compatibility troubles sometimes.
I am using WinRar 22.214.171.124 (64 Bit) version and I don't think I will change it.
So If you had this problem, I recommend you to install another archiver software (like WinZip, 7-zip, ...) and to try again.
If you still have that kind of troubles, please tell me by sending a comment on the appropriate post.