I am running Mac OS Sierra (10.12) on a Mac Mini (late 2012). All was working fine for a few days and then the Drobo disappeared from the Finder. Drobo Dashboard shows everything as fine and all the lights are normal on the Drobo. I ran disk utility and First Aid and it ran successfully without errors detected. I have safe shutdown the Drobo and switched it to another USB port (it’s never been on a hub). Has anyone else had this problem? I realize that Sierra is not “officially supported” but wanted to make sure this problem wasn’t unrelated before going back to 10.11.
Edit: FYI for anyone else with this issue. I used Time Machine to restore to 10.11. I purchased Disk Warrior (ouch). Disk Warrior fixed the directory issues and all is good now.
TL/DR; Buy Disk Warrior