Fixing Screenshots in MacOS

This was driving me insane. For years, I have been using Command-Shift-4 to take screenshots on my Mac. When you hit that keypress, you get to select a region of the screen, and the result gets placed on your ~/Desktop directory.

Recently, the feature stopped working.

I first blamed Dropbox settings, but that was not it.

I read every article on the internet on how to change the default location, restart the SystemUIServer.

The screencapture command line tool worked, but not the hotkey.

Many reboots later, I disabled System Integrity Protection so I could use iosnoop and dtruss to figure out why screencapture was not logging. I was looking at the logs right there, and saw where things were different, but could not figure out what was wrong.

Then another one of my Macs got infected. So now I had two Mac laptops that could not take screenshots.

And then I realized what was going on.

When you trigger Command-Shift-4, the TouchBar lights up and lets you customize how you take the screenshot, like this:

And if you scroll it, you get these other options:

And I had recently used these settings.

If you change your default here, it will be preserved, so even if the shortcut is Command-Shift-4 for take-screenshot-and-save-in-file, if you use the TouchBar to make a change, this will override any future uses of the command.