The majority of current apps that support macOS 10.12 Sierra require an update for capability, and a few mainstream Mac apps still haven’t been updated and have known issues including:

If the developer doesn’t claim compatibility with Sierra, then it’s pretty much use-at-your-own-risk when it comes to older Mac apps.  Some apps may work fine, others may have bugs, and a few just won’t launch at all.  It’s amazing how much a free Mac operating system upgrade ends up costing companies that haven’t upgraded their apps in a while.

Here’s a few older Mac apps I’ve run across that I can confirm will not work with Sierra at all:

  • Extensis Suitcase Fusion 6 and older (upgrade to Suitcase Fusion 7 or Teamsync)
  • Parallels Desktop 9 and older (upgrade to Parallels 12)
  • Quicken Essentials (upgrade to Quicken 2016)