Recording not working, macOS Mojave (and higher)

Since the availability of macOS Mojave we sometimes get enquiries with the info that recording audio signals in some applications is no longer possible. This can affect popular audio applications such as Bitwig Studio, Logic Pro X or GarageBand and it is actually related to a security setting that possibly prevents audio recording due to privacy settings. Only in some cases it is possible that you get an alert that says audio input isn't accessible when trying to record.

To fix this, go to System Preferences and click on Security & Privacy > Privacy > Microphone. The following dialog will appear:

In this dialog, select the checkbox next to the application to allow it to access the your audio hardware for recording. Now you can open (or restart) that application and start recording again.