When attempting to install REAKTOR 5 on macOS 10.15 (Catalina) or higher, the installation fails with an error:
Installing Reaktor 5 failed: An unknown error occurred
REAKTOR 5 is a legacy product and is not compatible with macOS 10.15 or higher.
Please see these articles for more info regarding macOS 10.15 (Catalina) or macOS 11 (Big Sur) compatibility with NI Products.
We recommend updating to REAKTOR 6. You can purchase an update from this link.
Alternatively, in order to use REAKTOR based instruments and effects, you can download the free REAKTOR 6 Player from here.