I have a solution for Lightroom Classic and thought I would share.
I believe the issue here is that the initial part of the DXO Free NIK Tools is a 32bit application. Big Sur only allows 64bit installers.
The work around is a little awkward, but does allow you to keep using the tools.
Check out this 15 minute video to get the basic concept.
So - Step by step…
- Download the new Version 3 DXO NIK Tools and install.
This is a necessary step as it effectively “sets” the MAC Big Sur system for the next steps - Uninstall the V3 DXO NIK Tools
- Download the Free version of the DXO Tools.
- Click to start the installation, but don’t install. Instead when you see the 2 large Icons, right click and select “Show Package Contents”.
This will open a Finder Window where you can navigate to Contents | Resources
In this folder you will see each NIK Tool’s installer for example “Define2.tar.gz” - Double click each tar installer.
You will now have separate folders for each Tool in the same directory as the main DXO_NikCollection.dmg - Open a new Finder window
- Navigate to “Macintosh HD | Applications” and create a New Folder. Name it Nik Collection
- Drag each Application from the folders you unpacked earlier into this new folder.
- As you do, each Application will now be available in the Mac Launchpad screen
OK - So we now have working stand alone Applications.
To add them to LightRoom Classic, add each App as a separate External Editor Program as per this instruction…