Potential issues when upgrading a 2015 MacBook Pro from macOS High Sierra to Catalina

There were some major changes in the OS with the release of macOS 10.15 Catalina.

❗️ – IMPORTANT – Backup your data before proceeding. (You’ve been warned.) In fact, make two copies of your stuff.

Back up your Mac with Time Machine - Apple Support

MacOS 10.15 Catalina dropped support for all 32-bit coded software. Your older 32-bit apps & drivers won’t work in Catalina or newer! They must be updated or replaced.  This includes Microsoft Office apps, Adobe, Photoshop, etc. Only 64-bit software will run in Catalina and newer macOS versions.

32-bit app compatibility with macOS - Apple Support

Use the free utility Go64 app from St. Claire Software to check if your current apps are 32-bit or 64-bit. Identify your 32-bit apps and device drivers – for printers and other peripheral devices – and know that it will have to be replaced.

In addition to the 64-bit software requirement, the drive format was also changed under Catalina.

Your current startup drive is likely formatted with Mac OS Extended (Journaled) format. The upgrade to Catalina will convert the format to APFS. It usually goes well, but if the conversion goes sideways, data may be lost. So, backups.

Those are the big changes that I recall. The 64-bit requirement is a showstopper for many.

TBH, your Mac is ten years old and obsolete by Apple standards. Upgrading to Catalina will gain you little to no advantage as you continue to use that hardware. Catalina is an obsolete OS. I know that you are having more and more trouble accessing web sites under High Sierra, but Catalina is falling down in that regard now, too. The Catalina OS coupled with the still supported Firefox browser is some help, but that support is due to run out soon, too.

Your 2015 Mac may be upgradeable to macOS 12 Monterey, which is two generations (years) newer than Catalina.

macOS 12 Monterey is compatible with these computers

However, Monterey is already four generations behind the current macOS version 26 Tahoe. Apple has stopped supporting Monterey by now.

You would be wise to consider replacing that obsolete MacBook Pro with a newer model, say something new or released not more than 3-4 years ago. That would allow you to run the current macOS and perhaps several newer upgrades as they are released. MacOS 27 Golden Gate is due out anytime now from Apple.

Trying to nurse your current hardware and software for a few more years will be no picnic.

yeshemama wrote:

I have a 2015 Macbook Pro that is running High Sierra 10.13.6. What issues should I be concerned about just updating to Catalina? I want to be sure I don't corrupt any of my older data especially family videos & pics

You can update a MacBook Pro (Retina, 15-inch, Mid 2015) as far as macOS 12 (Monterey).

If you update to Catalina or later,

• 32 bit applications will break
• iTunes will go away, replaced by separate applications (Music, TV, Books, Podcasts) and the ability to manage iPods / iPhones / iPads from the Finder.

Perhaps I should jump to Big Sur to get the ARM. Which dates and models are the ARM powered silicon Macs? hints for Wikipedia helped this low techie!

Installing Big Sur on your Intel-based Mac will not turn it into an Apple-Silicon-based (ARM-based) Mac. You will get the Intel version of Big Sur. Upgrading to Big Sur or Monterey would be recommended if you would like to run the LibreOffice office suite, or the GIMP photo editor. The current versions of both require Big Sur or better. Most third-party Web browsers other than Firefox now require Monterey or better.

As for Apple Silicon Macs, Apple released the first ones in November 2020. For a while, Apple carried a mixture of Apple Silicon Macs and Intel-based ones, but eventually they got rid of all of the Intel-based ones.

Most Apple Silicon Macs use M-series processors. There are two parts to each chip's name: a generation number (higher numbers indicate more recent designs), and a level (plain, Pro, Max, or Ultra). At the moment, all Macs that are in Apple's new lineup use M5-family chips, with the exception of

• The just-announced entry-level Mac mini, which uses a plain M6 chip
• The MacBook Neo, which uses a version of the A18 Pro chip originally used in the iPhone 16 Pro and 16 Pro Max

You're welcome.

There is nothing to do to avoid the potential pain of upgrading to Catalina, Big Sur or Monterey. And even if you do that, the Mac will continue to age out.

But your Mac will continue to work as it is now now for as long as the hardware doesn't break down. So perhaps using it as an archive for docs and photos is the wisest option.

I strongly advise, though, that you backup those docs and photos to an external drive as soon as possible, while you can and before some misfortune makes that a problem.