Re: And where is the fix?
>But unless someone tells us what the fix is and how to get it this information is totally useless.
From my reading of the MS KB's and the blogs.
1. If you have installed either of the two updates (highly likely), don't run Chkdsk /f, although you might be safe running chkdsk /scan.
2. The fix is being distributed via the WUP channel. It would not surprise me if the fix is listed with the same KB number as the original update, it just has a more recent version number/date.
So if your system isn't enterprised-managed, ensure all updates are installed - given how Win10 systems can go looking for updates claim your system is up-to-date, yet an identical system next to it can be downloading more recent updates, I suggest you can only really be sure the fix has been applied until after the January 2020 cumulative update has been applied.
If you have accidentally run chkdsk /f and thus have an unbootable system then you need to use a working system to create a recovery disk/bootable usb and use that to run chkdsk on the crippled system. It is probably best to create recovery media whilst you have a running system and make a full disk image backup...