Special Rack Modules

Thanks, that's it

No, its not working yet, how to get this aux module and this master module ?
I clicked everywhere and remember from the old versions Synfire it was somehow hidden.

For each Audio Engine you can add one AUX module to the Global Rack. It receives the signals from all AUX Send knobs of other modules, processes the mix and sends its own output to the MASTER module.

The aux module is a mix bus (channel) for a send effect as i see it now 

That is in Global Rack but it skould also be in the Arrangement Rack I belive?

Yes, must be , because there in the arrangement rack you need also fx 
A arrangement rack is a one time usable rack 

Correction: i opened the arrangement rack setup , but i don't see a aux or master module ?
But assigned already a aux and master module to global racks, so?

 Ah ..i do see it now within a minute when i start again with Synfire  : Its the rack Module library located in the audio/midi setup page and not in the arrangement view were also a rack module library exists.