I just installed Nik 4.1.1. on an external ssd, from which my Mac runs macOS Big Sur. After the installation, I clicked on “Finish”, waited a while and tried to eject the installer. Instead of doing so, macOS presented this:
I logged out and in and tried again. This time, I got:
I had to restart the Mac to get rid of the installer volume.
Ran the installer again and got the same behaviour.
Other than that, the installer seems to have done its job.
The uninstaller misses some text in german: