Unable to open Fritzing files



I am running Fritzing 9.3 on Mac El Capitan OS. Periodically lately, I’ve been losing projects. The latest one gives the following error message (copied and pasted verbatim):

Unable to open ‘/Applications/Fritzing/JB Fritzing projects/Bendo Box v5 5cm.fzz’: zip.open(): %d

With the exception of the file name, this has been the exact error I’ve gotten, and I’ve lost several really important projects. Does anyone here know what is causing this, and if there is there anyway of recovering these files?

Thank you in advance!


While I’m a Windows user rather than Mac, from the error message it appears the fzz (which is a renamed .zip file) is either missing or corrupted. Things to try: Check permissions and owner ship of the file (don’t know how in the gui on a Mac though :slight_smile: , if you are comfortable with the Unix command line

ls -l /Applications/Fritzing/JB Fritzing projects

would do it) If the file is there, check for zero length (in which case you may have or had a full disk which will truncate the file when it is written). If the file is there and has an appropriate size, rename it to Bendo Box v5 5cm.zip and try and open it with a zip utility (again don’t know the name on a Mac, I use 7zip which is open source and may also support Macs on Windows). Hopefully that will give you a better error message than Fritzing is and thus more of a clue as to what is wrong. Even better, perhaps someone familiar with Macs will give you some better suggestions :slight_smile: . In any case good luck! Backing up valuable files is always a good bet, but now is a little late to start if you haven’t been (but it is a good suggestion for the future in any case).


Terminal returned the following:
ls: /Applications/Fritzing/JB: No such file or directory
ls: Fritzing: No such file or directory
ls: projects: No such file or directory

The file “Bendo Box v5 5cm.fzz” is only 22kb according to finder. I don’t understand what’s happening, and why it’s only Fritzing that has this issue.


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 :slight_smile: ) 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.


My bad also…I misread the file size. There was an adjacent file that was 22kb. The file “Bendo Box v5 5cm.fzz” is only 22 bytes. I fear it is gone forever. Must establish a backup for this laptop…


Yes 22 bytes is a little small. Is it possible you ran out of disk space at some point? That is the usual reason for truncated files and error reporting is spotty about whether the truncation gets reported (the system call reports the fail but many programmers don’t check). For backup something as simple as a USB key that you copy the Fritzing files to when you have made major changes is an easy out.


hi , i have the same issue but i use window 10 , can you help me to fix this issue


You need to describe the issue first. If you create a sketch and save it you can’t reopen it or something else? Is this a new installation of Fritzing? If so did you stop it when it appeared to hang (when it was really trying to do a parts update from github)? There are a variety of possible problems and we need to know which one you have. You may also want to search for windows 10 in the forum search bar as there are a number of threads on problems here.