Well it was expectable that once again a big update
wouldn’t run without flaws. The Windows 10 Update
With Build 1809 has been pulled after several data
losses have been reported, although they are known.

Users of the Insider program have already reported that there might be some data losses upon updating the OS.

One user reported that the update has wasted some of his docs and images after the update and after the rollback the folders have been emptied out entirely.

Another user had a similar experience when updating.

Not quite encouraging to update anyways. And the pull of Microsoft is another proof that the update is far away from being sufficient to being released to the public.

Other users still willing to try an update process from recently downloaded installation media are adviced to do a complete backup to prevent data loss.