Several students and instructors reported that they could not unzip some of the zip files downloaded from CSNS. It turned out that the problem was not with the files but the software WinZip, which seems to have problem handling certain file names (e.g. file names with leading or trailing white spaces). The solution is simply using 7-Zip instead of WinZip. 7-Zip is free, open source, supports many compression formats, and is very easy to use. I highly recommend it.