Sorry, i forgot to mention that. Yes, after i changed to apple mode, the UC was detected and i updated the Firmware (416) first and than i installed the Driver. I works now, from what i can see without any functional limitations, but it shows the message i mentioned above when booting the mac.
some question reagrding your answer
"Anyway, I would try reinstall it. Carefully check all steps and enable the driver wherever needed.
MacOS System preferences Security&Privacy : scroll down check for big ALLOW-button
MacOS System preferences General Startup items and extensions click i-button in the RME."
You mean just to run the installer on top the existing installation, or do i need to uninstall first?
Is it possible to uninstall the flash firmware at all?
And with "General Startup items" – i don´t get that. Do you mean to add the totalmix to the "login items" under "user&groups" in system preferences ?
Again, thanks alot for taking to time to explain (maybe obvious things), waedi.
I appreciate it.