Splitter combiner note is not working in 12.5.5 studio on my Mac Pro 2009 Model MacPro5,1 Processor: 6-Core Intel Xeon Processorspeed: 3,06 GHz Number processors: 2 Total cores: 12 L2-cache (per core): 256 KB L3-cache (per processor): 12 MB RAM: 32 GB NVIDIA GeForce GTX 980/NVIDIA Quadro 4000 OS X 10.11.6 (15G1510) El Capitan Cheers, Stephan