Fix non-functional ImageJ after Update

 This section is out of date, potentially misleading or invalid. Be careful with any instructions here. When in doubt, ask for help from the community.

Unfortunately, there was a bug in the ImageJ updater that affected the update of the updater itself. The easiest way to get back a functional updater is to import this URL via File › Import › URL… .

If that does not work, please delete the files ij-ui-swing-updater-2.0.0-SNAPSHOT.jar, ij-updater-core-2.0.0-SNAPSHOT.jar and ij-core-2.0.0-SNAPSHOT.jar from the Fiji.app/jars/ directory (MacOSX users, Ctrl +click on the Fiji icon and select Open Package Contents and open the jars/ directory you see there). After that, the Updater should magically repair itself.

If that still fails, please download a fresh copy from here: