While developers optimize their apps for 64-bit compatibility, Apple is notifying customers when they are using an app based on 32-bit technology. This is done via a one-time alert that appears when you launch a 32-bit app. In macOS Mojave, this alert appears once every 30 days when launching the app.
Why am I seeing this alert?
Starting with macOS High Sierra 10.13.4, apps that have not been updated to use 64-bit processes produce a one-time alert when opened. This gives users advance notice that they are running 32-bit software, which will not be compatible with macOS in the future.
Can I keep using my 32-bit apps?
Yes, you may continue to use 32-bit apps with your Mac today. Using 32-bit software has no adverse effects on your data or your computer.
When will the 64-bit transition be complete?
The 64-bit transition for macOS and macOS apps is still underway, so final transition dates have not yet been established. But now is a good time to check with the software developer to see if 64-bit versions of your favorite titles are available.
How do I get in touch with the app developer?
The easiest way to contact a developer is to look them up on the web. To find the name of the developer of an app, open the app, then click the app name in the menu bar and choose ”About….”
How do I check if an app is 32-bit or 64-bit?
From the Apple menu, choose About This Mac, then click the System Report button. From the system report, scroll down to Software in the sidebar, then select Applications. When you select an individual application, you will see a field titled 64-bit (Intel). “Yes” indicates 64-bit; “No” indicates 32-bit. If you’re using macOS Mojave, select Legacy Software in the sidebar to see all applications that have not been updated to use 64-bit processes.
If you’re using Office 2011 (32-bit app) and you upgrade to macOS 10.14, it will no longer work.
You could replace Office 2011 with OpenOffice, you could purchase Microsoft Office with a subscription,or simply use Pages & Numbers for Mac.