Disable SIP in terminal
May give this a shot as well
terminal:
sudo spctl --master-disable
Double check your System Prefs/Security & Privacy/Privacy tab
fuzzy dudes workaround works, apparently not on your system.
MR rest won’t fix thing BTW. You could try Command+Option+P+R and wait till third bell with the MR unplugged. I bet after it boots and you shut down, reconnect the MR and boot up it will show up in About this Mac/System Report/FW, you will see it says MR there. However the software is NOT showing up for the MR console nor the FW driver. This is an OSX security thing ., I had SAME issue. Only thing that worked was running that AppCleaner and trashing everything FW, MR console, Yamaha etc and also trashing the prefs for the MR as well in Preferences. Then reboot, reinstall, reboot and FINALLY it worked here