Might as well remove it now, any plugins that placed it are broken anyway and if someone included it in a switch statement java will handle its removal safely. I doubt any ever actually used it in any other way since it had no use

The block doesn't exist anymore, see: http://minecraft.gamepedia.com/Locked_chest
See:

1.7.2
13w37a Removed locked chest as an item. The block can be placed only with /setblock.
13w41a Removed locked chest entirely. Stained glass now occupies its former data value.

How are you defining locked chest / As the one I am thinking of was only added in 1.8 and works perfect in both vanilla and CB/Spigot http://minecraft.gamepedia.com/1.8 .

I presume your referring to a really old lock,just wanted t check as part way though a plugin utilizing it..

Regards
Thk for the awesome work you guys have done over the past 6 months especially.

Relicum