Problem with the noise reduction effect

Hi Audacity Team, my operating system is Win 7 with Audacity 3.1.3 installed.
I have this problem: when selecting a trace stretch and apply the “noise reduction” function, pressing the “processa noise profile” icon, the message “Non-detectable value in the interval from 0 to 24” appears.
This also happens with version 2.1.2.
Can you help me?. Thank you so many.

Windows 7? So this could be a language associated decimal point delimiter issue. Can you set the sensitivity to 6,00? What if you use the slider ?

You could also try changing your language to English (“Edit menu > Preferences > Interface”).

The problem has been solved by changing the Italian language with the English one. Thank you very much