I have a number of edit bays that refuse to mount USB 3.0 hard drives. All of them are Mac Pro (trash cans) running 10.11.6, and a few weeks ago we never had an issue. I was just curious if anybody else is seeing the issue. Research showed me some scattered reports from 10.11.4 but nothings recent and no solutions. I am not sure if a security patch or anything was updated on the machines.
If we mount to a USB thunderbolt hub via USB 3 it works fine. Only the ports on the computer seem to be inert. Other devices like mice and keyboards and dongles work fine.