This applies to people using Diffraction Limited's MaxPoint software.

The recent Windows 10 1903 and/or related updates uninstall the Start menu link to MaxPoint.exe, and also uninstall the installer, so you can't repair it.
The fix is straightforward, and the details are here:

It is about a 5 minute task to get it going again.

On a related note, it is a good idea to backup your observations calibration data ".clb" from time to time, so that it is easy to restore in case of a PC problem.