Over time, you can accumulate several non-system based fonts on your Mac. Some of these fonts can be non-standard fonts which can cause some Apps to misbehave. Trying to determine which specific font is the problem is almost impossible. A better way to address font problems on your Mac is to restore your fonts to the standard default state in macOS. Here is how you do that.
Make no mistake, restoring fonts to the macOS default set is a big deal. You may have to reinstall some fonts that you use for special purposes. Here is what restoring fonts does on your Mac.
Since system fonts cannot be uninstalled on a Mac, restoring fonts does not install anything, as you might expect. Instead, it actually uninstalls all the “nonstandard” fonts that you have installed on your system. By “nonstandard,” Apple means any font that didn’t ship with macOS by default.
When you uninstall nonstandard fonts, you do not lose them. You can locate them in /Library/Fonts (Removed) or /Library/Fonts (Removed). You can reinstall some if you need them.
You uninstall nonstandard fonts in the Font Book App.
Once the App is open, click on the File Menu and select “Restore Standard Fonts”.
You will get a warning message like this one.
When you click “Proceed”, the nonstandard fonts are removed to the folders mentioned above. I am not going to remove the fonts from my machine, but it just gives you a complete message. It might be a good idea to do a Restart of your Mac after doing this. Remember, you can add some fonts back in if you need to do so, but I would do that judiciously.
If you have font problems on your Mac, then restoring standard fonts is not a bad idea.