So I have got a new (to me) fireface 800 running with fw800 to Thunderbolt2 adapter into mid 2015 Macbook Pro. on Mojave

Trying to install the driver between 2.9 or 3.39 I get the usual problem with no permission to access system pop up appearing. Tried all the tricks... using terminal to allow RME as vendor, disable SIPS, etc. nothing works.. the installer seems to run fine and then asks for reboot but then nothing is installed on reboot...

2.75 installer works... and then I can remove Totalmix and Fireface settings from the 3.39 installer package and use them... but the actual driver is still the 32bit 2.75. The fireface agent is also only 32bit.

So this is okay for now... but I can't upgrade to Catalina (exclusively 64bit) with this situation.

Total mix 1.64
Fireface settings 3.39
Fireface 800 Firmware 2.77
Kernal driver 2.75