windows 10 (October 2018 update) (version 1809) deleted all my files

I am wondering if this issue has anything to do with the addition of OneDrive to the Storage Sense utility (Settings->System->Storage) in the October 2018 Update, which will delete locally-stored files that haven't been opened for a set number of days.  I am also wondering if those who lost files had Storage Sense turned on prior to the update, and those who did not lose any files had it turned off.  Thinking even further, could it be that the update process is turning it on by default with a value for the number of days which is causing the utility to remove files?

I think you're on to something there, BarryG_961!

This helps me with a discrepancy I have noticed in the way the October Update has affected different users. I was looking for a common denominator for those who ACTUALLY LOST data rather than just had it arbitrarily relocated as in my case where I had to find about a terabyte of ostensibly missing data. I found it in C:\users\USERNAME as opposed to C:\users\USERNAME/Documents or any of the variations thereof.

Naturally I was thinking about a common make of computer or even of CPU.

But I uninstalled the OneDrive App when it first came in with Windows 10 back in 2015 and have never missed it. If I want to use OneDrive to store Data I just go to it via Edge.

https://onedrive.live.com/

Certainly if this is TELLING the computer to delete files and folders then that explains a LOT!

Good thought, and makes sense, but I don't have Storage Sense enabled, and have not ever had it turned on (before with 1803, and even after the 1809 install it's still turned off).  Besides, with folder redirection in play, you can't enable OneDrive sync.  I can see how none of my 'special folders' were impacted, given folder redirection and a cached copy locally.  But what doesn't makes sense is how a seemingly non-profile based folder was impacted.  Then again, reading some of the other posts, this seems to be all over the board and seems I lucked out -- all things considering.  I'm also guessing there will not be any rhyme or reason that MSFT will shed...

I am wondering if this issue has anything to do with the addition of OneDrive to the Storage Sense utility (Settings->System->Storage) in the October 2018 Update, which will delete locally-stored files that haven't been opened for a set number of days.  I am also wondering if those who lost files had Storage Sense turned on prior to the update, and those who did not lose any files had it turned off.  Thinking even further, could it be that the update process is turning it on by default with a value for the number of days which is causing the utility to remove files?

I think you're on to something there, BarryG_961!

This helps me with a discrepancy I have noticed in the way the October Update has affected different users. I was looking for a common denominator for those who ACTUALLY LOST data rather than just had it arbitrarily relocated as in my case where I had to find about a terabyte of ostensibly missing data. I found it in C:\users\USERNAME as opposed to C:\users\USERNAME/Documents or any of the variations thereof.

Naturally I was thinking about a common make of computer or even of CPU.

But I uninstalled the OneDrive App when it first came in with Windows 10 back in 2015 and have never missed it. If I want to use OneDrive to store Data I just go to it via Edge.

https://onedrive.live.com/

Certainly if this is TELLING the computer to delete files and folders then that explains a LOT!

Sorry for the loss of your VM file. Not only does it exceed the capacity of a normal OneDrive, but it breaks this rule...

https://support.office.com/en-us/article/sync-your-documents-pictures-and-desktop-folders-with-onedrive-d61a7930-a6fb-4b95-b28a-6552e77c3057

Sync your Documents, Pictures, and Desktop folders with OneDrive

"File exceeds the maximum file size: OneDrive can't sync files over 20 GB. Remove these files from the folder you want to protect and then try again."

Looks like 1809 set it as default to protect the contents of those folders. But the feature couldn't handle it when a rule was broken. And your VM file now swims with the fishes.

It sound like a Kafkaesque data proteciton racket, I never asked for OneDrive to begin with. But anyhow I am genuinely happy that they pulled the update and that prosperity won't be talking of the Microsoft great October Document Purge (MODP). If they did roll it out over 150 or so million clients with a high percentage of affected systems then the amount of lost work would be mind boggling. Its probably a lot more then the hours spend on building the pyramids and going to the moon put together. Pulling it certainly avoided some bankruptcies and might even prevented some suicides. 

I hope this worst case "near hit" will be study material for OS developers and will galvanized the patch testing processes.

Yes I know. Much more information has come out since I wrote my original response and I have made much more recent and more enlightened comments since that one.

I lost 30gbs,  all of my documents are GONE. I am VERY UPSET.

I ran EaseUS and was able to find the files, same size & same description but couldn't open or preview any of them, files got corrupted i think so i tried to recover at least the pictures but no dice...