However shall I cope without my emojis?!

I had an issue where pressing option + ctrl + spacebar would bring up the emoji menu. However it would not let me insert it into whatever text I wanted (I like putting emojis everywhere in my code when debugging).

In Terminal.app

rm -rf ~/Library/Preferences/com.apple.CharacterPaletteIM.plist
rm -rf ~/Library/Preferences/com.apple.CharacterPicker.plist

You could probably move them (as a backup if you so wished):

mv ~/Library/Preferences/com.apple.CharacterPaletteIM.plist_backup
mv ~/Library/Preferences/com.apple.CharacterPicker.plist_backup

Now reboot.

And have fun emoji spamming everyone. 😇