The Windows 10 upgrade 1809 just released on 3rd Oct 2018, has a bug.
It supposedly has been re-released after having the bug ironed out but there still complaints from users trying to update.
Only a small number are affected ; but there is no way of ensuring that it wont happen to you.
Advice is HOLD Back for the time being. If your version of Windows allows updates to be postponed (go to Settings -> Updates & Security -> Advanced Options and Pause updates)
Some versions of Windows 10 especially the Home edition may NOT allow the option to delay updates.
Since the bug causes loss of files from your computer it is strongly recommend to do the following:
Create regular restore points and backup personal data as a precaution. More information via the link below
The information posted on this blog is hopefully accurate but there is no guarantee - it's always best to check with the appropriate persons before making any commitments!