I know this is going to sound like a total jerkwad for saying this, but I always wait until other people install major Windows 10 updates so they can be the guinea pigs, instead of me.
Numerous users across the web reported that the transition deleted massive chunks of data. User profiles and entire folders full of files went missing in some cases and rolling back the upgrade didn’t restore them. Now Microsoft is temporarily halting the October 2018 Update’s distribution due to the issue.
