Research IT

macOS Catalina Upgrade

This month’s Top Tip article comes from Ian Cottam and Ian Hinder, two Research Software Engineers from Research IT. They advise caution regarding the September 2019 major update to Apple's macOS - macOS "Catalina" (10.15 as a version number).


Many UoM researchers use Apple Macs and it is also common for users to update to the latest version. Such an "early adoption" process is not always wise, and for some people using older Mac software, that will be especially so in this case.

Microsoft and Apple have very different approaches to the on-going compatibility of software applications. Microsoft pride themselves on business continuity – an application written and compiled for say Windows XP will still run well on today's latest Windows 10 release. Apple, in contrast, tend to discard features they regard as obsolete for the sake of progress.

macOS Catalina will NOT run any 32-bit application. If you double-click on one you have already installed, it will just result in an error message. Most major applications should have 64-bit versions by now, but there are always exceptions. Below is how to check what you have on your Mac, and with a link to further information.

You can find out which installed applications are not 64-bit by going to:

  • Apple Menu
  • About This Mac
  • System Report
  • Software > Applications
  • In the last column, you can see whether it’s a 64-bit application or not. You can click on the 64-bit column heading to sort by it and group them all together.

For more details about this issue we recommend visiting this website as it goes into a little more detail.

There is some good news - Microsoft Office 16 for macOS is 64-bit!

Ian Cottam writes: "I, for example, have lots of old 32-bit apps and need to check carefully which I still need and which have upgrades. I will be staying with macOS Mojave (10.14) for the foreseeable future."

If you have any queries about how this update may affect you, please get in touch!