Installed HS on a new iMac running 10.12.6. Needless to say, HS f*ucked up my comp. Passwords all screwed up including my Apple ID, Dock kept getting stuck, as well as my cursor, updates not showing in Apple Store & worst of all, Time Machine kept telling me "Disk not connected." A lot more other strange happenings. Been using Macs since 1999 & this is the first time EVER I had to downgrade.