Steinberg has released a new version of the Steinberg Yamaha USB driver for Mac.
The version 1.9.6 of the driver now officially supports OS X 10.11 (please read the updated information here: http://www.steinberg.net/en/newsandevents/news/newsdetail/article/usb-audio-interfaces-now-incompatible-with-el-capitan-3443.html)
Hardware products supported by this driver version are:
UR series: UR12, UR22, UR22mkII, UR28M, UR242, UR44, UR824
CI series: CI1, CI2, CI2+
Please find the driver update here.