HotHardware writes some Windows 10 users are having issues with user profiles and settings after the installation of the KB4532693 Update. It's not the first time a Windows 10 update causes issues but this seems to be another patch that may be worse than the problem it tried to solve.
Some users who installed the update say the user profile goes missing. There have also been complaints of custom icons and settings getting wiped with the desktop and Start Menu being reset to default, and desktop files going missing. It's not yet clear how widespread the issue might be, and as of this writing, Microsoft does not list any known issues associated with KB4532693.
The issue seems to be caused because the installer loads a temporary file during the installation, but in some cases it fails to revert to the original user profile when the installation is finished:
What appears to be happening is on some Windows 10 PCs, the update is loading a temporary file during the update process, but failing to revert back to the user's profile when finished. The update is essentially tripping over itself, causing headaches for affected users. Fortunately, this does not result in any data actually being deleted, as happened with the train wreck that was the initial roll out of the October 2018 Update.