macOS 10.14 Mojave & macOS 10.15 Catalina require the user to enable microphone access. Without allowing access for Serato DJ Pro, you may experience issues such as (but not limited to);
- Lack of DVS signal
- Lack of recording signal
- Assorted audio issues
You should be prompted by macOS when first launching Serato DJ Pro (may require your Serato hardware to be connected), with the following messaging in which you will need to choose 'OK' to allow microphone access:
Without doing so you will experience some of the issues listed above, but in case you chose 'Don't Allow' or ignored the prompt, you can also retrospectively adjust your settings to rectify permission (you will need to 'click the lock to make changes' and enter your log-in details to adjust the settings below):
System Preferences → Security & Privacy → Privacy → Microphone → Serato DJ Pro → (enabled)
NOTE: Depending on your Serato hardware's need for internal inputs, you may not see the prompt for microphone access further above, or need to enable the microphone access under Security & Privacy.