Just downloaded FIJI, and the .exe won't run saying "Could not find ij.jar"


I just downloaded the .zip and extracted to my desktop. When trying to run the .exe the error “Could not find ij.jar” comes up. I searched in the folder to see if it was in the wrong location, but there is no ij.jar file at all.

This has been reported in another post, but the suggested fix of checking all files were extracted did not resolve the issue:

Does anyone know a way of resolving this?

Many thanks

In case anyone else has this issue, I was unable to get the fiji-win64 zip to run as the .exe kep throwing the error described above, however, the Fiji Life-Line version, 2015 December 22 (windows) unzipped and is running fine for me.

No idea if this is an issue on my end, of if there is possibly a problem with the fiji-win64.zip

By “the folder” do you mean inside the Fiji.app folder? The location of the ij.jar file should be in Fiji.app/jars, and it will probably be called ij-1.50e.jar (the error message leaves out the version number).

I just downloaded a Win-64 Fiji, and it looks like the ij-1.50e is there. So if your installation is missing that file, it sounds like something interfered with your download or the extraction process.

If your file is in the Fiji.app/jars folder, ImageJ may not be looking in the right place. Did the error message include any indication of where it was looking? If not, you can try running:

imagej-win64.exe --dry-run

from the command prompt. If you could paste that information here we can see if it helps diagnose what went wrong.

Good to know. Did you try updating the lifeline version to the latest with Help > Update...?

Thanks for the report and follow-up!


I did indeed. I can’t see any ij.jar in Fiji.app/jars, see the scree grab. I think you may be right that there was a problem extracting the archive. While I was unable to unzip it on my machine using 7zip, a friend I sent the .zip to got an error message the archive was corrupt when they tried extracting it with winrar, they could not get it to run after several attempts.

I have now, and it successfully upgraded to v1.50

No problem, cheers

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Others have reported corrupted downloads as well. We have plans to change how we serve these files from the web site, to prevent this issue in the future. In the meantime, downloading a Life-Line version avoids the problem.