Hi all; I have been having issues with consistently mounting and ejecting external drives since installing MacOS 10.11.3. Sometimes they would mount after restart, sometimes not. When they do mount, I may need to go into the Activity Monitor and deselect mdworker. I thought I had resolved the issue by getting a powered USB3 hub, but that is also not consistently working. I have three WD drives with USB connections. I also have a LaCie external with a FireWire connection and that works consistently. The issue presents on my 27" iMac but not on my MBPro nor MBAir; all running 10.11.3. Any ideas?