Can't use Channels Tool on freshly downloaded Fiji on Mac

Hi *,

I encountered a problem today and first thought this is just my Fiji that might be broken for whatever reason. Unfortunately, downloaded the latest version leads to the same behavior.

Please see the attached image. I cannot switch between Composite, Color, and Grayscale in the drop down menu in the Channels Tools (cmd+shift+Z). The drop down would close so fast again, that it is impossible to switch between those display modes (it seems that the Fiji main window immediately gets the focus back, thereby closing the drop down).

Is this also happening to others? Anyone a clue why this happens and how to fix it?


PS: if this is already looked at by someone… for quite some while there is another quite annoying UI change on Mac. The cmd+shift+C (Brightness&Contrast) window does not open with ‘Auto’ being the default button. Cmd+shift+C plus the space bar was for years (and is still on other OSes) the keyboard-only quickest way to auto-contrast the current image. I would LOVE to see this work again on Mac.!

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Please see the discussion in this GitHub issue:

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The latest ImageJ daily build (1.52q44) has an untested fix for this problem. Please try the daily build and report back. To upgrade, use the Help>Update ImageJ command and select “daily build” from the drop down menu. The source code changes are at

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This regression on macOS is fixed in the latest ImageJ daily build (1.52q44).

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Thanks a lot! Will try as soon as I’m back at a Mac! :slight_smile:

Hey all, just downloaded the latest updated Fiji today on a MacBook Pro – the channels tool is still doing the thing that @fjug described. Fjug, are you still experiencing this problem?

Are you running Image 1.52q or later? It has a Channels Tool bug fix. Use the Help>Upgrade ImageJ command to update.

I’m running v1.52p – I don’t see an option to upgrade to v1.52q. Is
v1.52t a later version than 1.52q?

V1.52t, the current version of ImageJ, is a later version than 1.52q. I do not know why Fiji does not include the latest version of ImageJ.

Grand, thanks – it works now!