Well, at least we have the details. And oh, the company has also restarted the rollout of the October 2018 Update after figuring out exactly what went wrong.
For Insiders, at least.
Apparently, a change made to the Known Folder Redirection (KFR) feature is to blame here.
If you’re out of the loop, Microsoft pulled the latest version of the operating system after officially acknowledging a bug that led to the deletion of certain user files. The above feature technically allows users to redirect known folders like the Windows libraries and the desktop to a new location.
But folks who deployed the October 2018 Update started reporting that KFR created an empty folder on their device, and the software titan put new code in Version 1809 to prevent this from happening.
“That change, combined with another change to the update construction sequence, resulted in the deletion of the original “old” folder locations and their content, leaving only the new “active” folder intact.”
The company further provided details that there were 3 different issues with the existing implementation of KFR in the Windows 10 October 2018 Update.
Unexpected behavior, thereof.
You can read up on the details at the link above.
But long story short, Redmond has resumed the delivery of Windows 10 Version 1809 for Insiders with fixes for all these bugs. Since users in the Fast and Skip Ahead rings are already on Windows 10 19H1, the company is using the other two rings to test this new OS image.
That being, Slow and Release Preview rings.
No ETA on when the October Update will be available for everyone, but Microsoft apparently wants to run a series of tests first and only then release this new version to all users.
No hurries, though.
None at all.
Just make sure no one else suffers from these surprising little bugs.