Fiji Cannot open on MOS Catalina

Hi, Just wondering if anyone else that has MOS Catalina installed and can’t get Fiji to open or if anyone has got around it yet??


Check out this older thread:

Welcome to the forum, @charlynewms!

There is a trick on macOS: after unpacking Fiji and dragging it to /Applications, right-click the icon and choose Open. It should pop a dialog warning you that the program is from an unidentified developer, but allow you to click the Open button to launch it anyway. Once you do that once, it should work to simply double-click after that.

At least: that’s what has worked in previous recent macOS versions. And I read that it still works in Catalina. But I admit I didn’t upgrade to Catalina—nor would I recommend most people upgrade yet, since there are many downsides to doing so. If the right-click Open trick does not work, please let us know, and we’ll investigate further.


If anyone else has come across this problem, I can confirm deleting your fiji app and re-installing will fix the problem. I just did this on my MacBook.

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Thanks a lot for confirming, @hbrown227! And welcome to the forum. :sun_with_face: