For anyone who's never seen this before:

There are two lines missing there, when they did the translation they accidentally used string terminators ($00) instead of linebreaks ($01) so the other lines are never shown. What it was supposed to be:

To fix it go to headered offsets 0x0DC01 and 0xDC0D and change the $00 bytes to $01.
So why was this never caught during development? Chances are it's because two-handed weapons are grayed out when you have a shield equipped, the testers probably never even thought to try equipping one of these weapons without removing the shield first. I'm guessing two-handed weapons aren't supposed to be grayed out when you have a shield equipped, you'd try to equip the weapon and get this message.
If anyone's curious about the odd indentation, that's because it's identical to the Japanese version:

Had someone actually stumbled onto this string before release the linebreaks probably would've been fixed and the text centered properly.
Interestingly there is a similar string found with the rest of the equipment menu text in the GBA version, it is never used though. It may be a leftover from the WSC version, if anyone has a save in that with a two-handed weapon handy take a look and see.