Hi, I connected my UASP-supported drives (an ASMT 2105-based enclosure and a Transcend JetDrive USB SSD) and when analyzing ioreg, IOUSBAttachedSCSI didn't appear in the logs when connected in El Cap. However, the devices were connected via IOUSBAttachedSCSI successfully in Yosemite. Can anyone else test this issue as well? Thank you. Run ioreg > ~/Desktop/ioreg.txt and open the txt file that was created on the Desktop, and search for IOUSBAttachedSCSI.