Hello,
We have released a new Yamaha Steinberg USB Driver v1.9.7 addressing the audio-dropout issues that occurred on Mac OS X 10.11.1 (El Capitan).
Please find the driver on the download page!
This driver is compatible with all UR Series and CI Series devices. If available, make sure to have the latest “TOOLS for UR” or “TOOLS for CI” installed for your device prior to the installation of the new driver.
Thank you!!
I’m still getting dropouts 
Host: Apple iMac 5k 27" (Late 2014), OS X (10.11.1), 4GHz Intel Core i7, 32GB RAM, 256GB SSD OS Drive, Samsung T1 for samples.
Slave: Windows 10 Pro, Intel Core i7 6-Core i7-5930K (3.5GHz), 64GB RAM, 1TB Samsung 850 EVO SSD for samples.
Hardware: Oxygen61 Midi Keyboard, UR22 Interface, Yamaha HS7 Monitors.
Software: Logic Pro X, VEPro Server.
Then please post in the UR forum section only. This is the CI forum. Thanks!
It works perfectly, thank you!