NOTE: OS X 10.9.1 (and perhaps 10.9) seems to have a bug that makes it hard to delete preferences. Even after deleting the appropriate preferences file, the data itself seems to stick around somewhere. After deleting the preference files, you should reboot your computer to flush the cache. This seems to even result in a crossover of preferences from the App Store version to the non-sandboxed version. So, if you're having trouble and are deleting the prefs to try and fix, be sure to reboot.

Sometimes you need to access Composer’s setting files directly to view them, or to delete them when troubleshooting.

SHORTCUT: In Composer's Preferences, go to the Appearance pane and hit the "Open Styles Folder" button. This will ensure you are inside the proper folder. You can then navigate upwards to find the Preferences folder as well.

MultiMarkdown Composer v2 - Mac App Store Version

Sandboxed applications store their files in a strange place.

Styles and the receipt copy go here:

~/Library/Containers/com.multimarkdown.composer.mac/Data/Library/Application Support/MultiMarkdown Composer

Preferences go here:

~/Library/Containers/com.multimarkdown.composer.mac/Data/Library/Preferences/com.multimarkdown.composer.mac.plist

If you really can’t get things to work, you can try deleting the entire directory:

~/Library/Containers/com.multimarkdown.composer.mac/

MultiMarkdown Composer v2 - Non-Sandboxed Version

Styles and the receipt copy go here:

~/Library/Application Support/MultiMarkdown Composer

Preferences go here:

~/Library/Preferences/com.multimarkdown.composer.mac.plist

What Does “~” Mean?

“~” is equivalent to your user directory

In the Finder, “Go->Go To Folder” and paste the appropriate information in.

Composer’s Preference window also has a button to take you directly to the Styles folder.