Sorry, my bad, forgot the quotes. Try
ls -l "/Applications/Fritzing/JB Fritzing projects"
as well do an
ls -l ./
(which will display your current directory and give us your userid and group information to compare with that of the "/Applications/Fritzing/JB Fritzing projects" file). The blanks in the file name act as delimiters (and it looked for "/Applications/Fritzing/JB" then "Fritzing" then "projects" none of which will exist). My best guess without the errno value from the error message is that you have an ownership or permissions problem. The " zip.open(): %d" in the error message is likely a Fritzing bug, as the %d should be a number indicating what error happened on the open, but it looks like someone forget to add the errno variable to the end of the printf statement in Fritzing. Are you using more than one user ID on your Mac? I suspect that your files are owned by a different user id than you are logged in as and the error number on the open would likely be permission denied if it were being displayed. I suspect your files are probably fine as the error seems to be on file open rather than when it is trying to unzip them and you just need to modify the permissions so you can read and write them from the user Id you are using. The file being 22k sounds reasonable (0 would be unreasonable and of concern 
) Fritzing files aren't usually all that large so I expect the files are fine and as noted permissions are the issue and if we correct that things will work.