At Apple's Worldwide Developers Conference (WWDC) in June 2018, it informed software developers that macOS Mojave (10.14) will be the last version of macOS to run 32-bit apps.
It is widely expected that during this year's WWDC, Apple will announce macOS 10.15 and your older, 32-bit software will NOT work anymore once you've upgraded your Mac's operating system to the new 10.15 version.
... (1) Upgrade that particular software package to a 64-bit compatible version (if available, but some software packages will never be upgraded by the developer) or replace it with a competitor's offering that is 64-bit compatible.
... (3) Consider having one Mac running the newest operating system and 64-bit programs as well as an older Mac for when you need to run those older applications on which you may rely.
