If your device is an older version, it won’t support Catalina. Trading 32-Bit for 64-Bit. Perhaps the most major change in macOS 10.15 is the switch from 32-bit apps to 64-bit apps. This has to do with how much RAM an app can use. Older apps may be 32 bits, and they won’t run on Catalina. However, you can still click on the “OK” button to continue using the app. Unfortunately, this is no more possible with macOS Catalina. When the 32-bit app is on the dock, you will see a white cross mark on the app indicating it will not work any more.

When a new version of macOS comes out, I usually upgrade my computer relatively soon. I like having access to the latest features, and significant macOS release upgrades are generally trouble-free. That hasn’t been the case with the newest version, Catalina. The trouble stems from the fact that Catalina doesn’t run 32-bit applications. While most major software in the system is now 64-bits, there are still some stragglers — especially legacy apps and drivers that haven’t been (and likely won’t be) upgraded.

That’s why I waited longer than usual before upgrading to Catalina: there was one application in my system that was 32-bits, the driver for my Fujitsu ScanSnap S300M scanner. I knew this driver was incompatible because every time I launched it (under Mojave, the previous version of macOS), I’d get a warning saying that the app would not run in the future. (Here’s a way to learn which apps won’t work: under the Apple menu, go to About this Mac > System Report… > Legacy Software.)

Without this driver, the scanner is useless — even though the hardware is perfectly functional. This device is an important part of my workflow; I use it every other week to digitize most of my paper documents and correspondence. Fujitsu no longer sells this model and has no plans to release 64-bit drivers. So I was stuck. I had two choices: I could hold off on upgrading the operating system (for a while), or I could buy a new scanner. I didn’t like either option. Sooner or later, I’d have to upgrade the OS. And as I said, the scanner itself was in perfect condition; I didn’t need a new one. What to do?

/quick-key-mac-app.html. It turns out there was a third option: look for an alternative driver. I found a third-party application called VueScan that works with a range of scanners, including the S300M. It’s been working well for me; the only downside is that it’s a bit slower than Fujitsu’s driver. But given my use of the scanner, it’s not slow enough to merit buying a new device.

32-bit X64

Thus far, Catalina has been great. Make a windows java based app work on mac. I’m especially enjoying the new Sidecar feature, which allows me to use my iPad as a second screen when I’m on the go. So far, everything is working for me — including my old scanner. The lesson: if you’re contemplating upgrading to Catalina, but are holding back because of legacy software on your system, consider looking for alternatives.