Snake minigame error.

26.04 21:25:18 [Server] INFO ... 3 more
26.04 21:25:18 [Server] INFO at org.bukkit.craftbukkit.v1_7_R3.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:53)
26.04 21:25:18 [Server] INFO at org.bukkit.craftbukkit.v1_7_R3.scheduler.CraftTask.run(CraftTask.java:58)
26.04 21:25:18 [Server] INFO at com.comze_instancelabs.snakechallenge.Main$15.run(Main.java:1066)
26.04 21:25:18 [Server] INFO at com.comze_instancelabs.snakechallenge.Main.access$0(Main.java:1080)
26.04 21:25:18 [Server] INFO at com.comze_instancelabs.snakechallenge.Main.initPlayerMovements(Main.java:1099)
26.04 21:25:18 [Server] INFO Caused by: java.lang.NoClassDefFoundError: com/comze_instancelabs/snakechallenge/v1_7_2/MESheep1_7_2
26.04 21:25:18 [Server] INFO at java.lang.Thread.run(Thread.java:744)
26.04 21:25:18 [Server] INFO at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
26.04 21:25:18 [Server] INFO at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
26.04 21:25:18 [Server] INFO at org.bukkit.craftbukkit.v1_7_R3.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:56)
26.04 21:25:18 [Server] WARN org.apache.commons.lang.UnhandledException: Plugin SnakeChallenge v1.0 generated an exception while executing task 60518
26.04 21:25:18 [Server] WARN Exception in thread "Craft Scheduler Thread - 144"