Error when shutting down server

This error occurs when running shutdownserver in game and when we shut down through Rcon tool. The error is spammed until I force close the server.

java.nio.channels.CancelledKeyException
at sun.nio.ch.SelectionKeyImpl.ensureValid(SelectionKeyImpl.java:73)
at sun.nio.ch.SelectionKeyImpl.interestOps(SelectionKeyImpl.java:82)
at de.jiw.network.kernel.tcp.TcpKernel.run(TcpKernel.java:248)

Here is the part just before the error starts.

LOADPLAYER: fuzzyfreak
[LUA][Zcript] 10/15/15 09:11:09 INSERT INTO `lastlog` (`player_id`, `name`, `ip`, `connect_at`) VALUES (64, 'fuzzyfreak', '0.0.0.0/0.0.0.0:4255', strftime('%s', 'now'));
PLAYER CONNECT DONE!
*************** NEW THREAD LOCAL ALLOCATION ***************
*************** NEW THREAD LOCAL ALLOCATION ***************
*************** NEW THREAD LOCAL ALLOCATION ***************
*************** NEW THREAD LOCAL ALLOCATION ***************
*************** NEW THREAD LOCAL ALLOCATION ***************
[LUA][Zcript] 10/15/15 09:11:15 ** fuzzyfreak - joined the Server
*************** NEW THREAD LOCAL ALLOCATION ***************
*************** NEW THREAD LOCAL ALLOCATION ***************
*************** NEW THREAD LOCAL ALLOCATION ***************
WARNING: SERVER WILL SHUTDOWN...
java.nio.channels.CancelledKeyException
at sun.nio.ch.SelectionKeyImpl.ensureValid(SelectionKeyImpl.java:73)
at sun.nio.ch.SelectionKeyImpl.interestOps(SelectionKeyImpl.java:82)
at de.jiw.network.kernel.tcp.TcpKernel.run(TcpKernel.java:248)