Because Audials Music Recorder is a third-party company product bundled with Nero Platinum. 

Unfortunately, we cannot provide technical support on this third-party product at Nero side.

 

For technical assistance related to the Audials Music Recorder, please contact Audials support directly:

https://support.audials.com/hc/en-us/requests/new

 

Below link is a good sample that one customer reported same issue as yours and it seemed he has got Audials Support already:

https://support.audials.com/hc/en-us/community/posts/360003223499-problem-to-activate-music-recorder-with-nero-platinum