cant join world in multiplayer due to a too long string

i was bussy with command blocks when i was kicked from the server i says
Internal exception: java.io.IOExeption: Received string length longer than maximum allowed (69>16)
i cant join the world again i've tried it with a bukkit server and a vanilla server
other people also cant join the server. i've deleted the command block i placed just before i was kicked with MCEdit but i still cant join. only on single player