I installed NEW upgraded Native Access and was told that it does not work with my operating system...
You can find older versions here - Native Access Legacy Installers for Older Operating Systems – Native Instruments (native-instruments.com)
Also know that just because you get an older version of NA working on that old MAC - NA v1 is being rapidly phased out and there are already existing software updates that are not available in that version.
If you want to get full value out of your NI investment - it's time to consider moving past OS 10.14 - like soon.
VP