Missing language string 'death.attack.magic.player'

This is the message given when you are killed by some form of potion (or other magic means) while fighting another player.

It should display as:

%s was killed by magic while fighting %s

%s was killed by magic while fighting %s

However, it displays as:

death.attack.magic.player

death.attack.magic.player

An easy way to fix this is to add the language string into the default language files. Simple.