Our investigation has shown that running “CleanMyMac 3” app is a root cause for this issue. CleanMyMac 3 interferes with S.M.A.R.T. subsystem of OS X, so that even Apple’s Disk Utility can’t work properly, it reports “S.M.A.R.T. status: Not supported” for all drives when CleanMyMac 3 is running. Turn off CleanMyMac 3’s menu bar item until MacPaw will not fix this bug.
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