The notices about 32-bit applications installed on Macs with macOS High Sierra 10.13.4 continue to appear and is that by now they should all be updated for 64-bit. If you are one of those who uses 32-bit applications on the Mac It is possible that you already saw the warnings that the system launches.
Developers can no longer release 32-bit applications on the Mac App Store since the beginning of the year. On the other hand, the warnings keep coming and it is assumed that in the new version of macOS 10.15 that Apple will launch at the WWDC in June, it will be the turning point and these will no longer be supported.
Apple warns you by active and passive
These applications that are not up to date show a notification and this is not repeated constantly, but it does when you turn off the computer. Apple itself reported it in a statement in January:
The latest version of macOS to support 32-bit applications without compromise is macOS High Sierra. Make sure future versions of your application are 64-bit compatible by using the new diagnostic tools in Xcode 9.3 beta and testing in macOS 10.13.4 beta. This version of Xcode also builds 64-bit applications by default. - Manzana
What to do if we receive a notice
In principle we do not have to be afraid of it, since the application will continue to work the same despite the warning, the important thing is to update to 64 bits as soon as possible. If you are one of those who wants to know which applications are 32-bit and are installed on your Mac, you can do it in a very simple way by following this small tutorial on how to find all 32-bit applications installed on our Mac. In short it is simple and the operating system itself will warn us of this.