I have had a few experiences where older “legacy” software worked in Windows 10-1709, but it won’t work in Windows 10-1809 (in all cases, Windows was 64-bit):
* Webroot
* LaserLink 2018 (Tax prep software
* Fed Comp (proprietary credit union software)
The version of Webroot was really old; a newer version is available. We haven’t finished working this one yet.
In the case of LaserLink and Fed Comp, I uninstalled the software, then reinstalled it (and running it) using Compatibility Mode (Windows 7 rules).
Using Compatibility Mode fixed the problems with LaserLink; insufficient testing has been done on FedComp.
Moral of this story: If you have older software, and it won’t run in Windows 10, install it and run it in Compatibility Mode (allows you to use the rules of a previous version of Windows). This will probably fix the problem, and it is a very easy fix.