Bukkit

What steps will reproduce the problem?
1. Install Spigot 1.8.8
2. Install Plugin
3. Run server

What is the expected output? What do you see instead?
No error at all...

Version to use:
1.2.5.176

Logfile Extraction:
Console : [20:35:39 INFO]: [Statistics] Connection is still present. Malformed query detected.
Console : [20:35:39 WARN]: Exception in thread "Craft Scheduler Thread - 1015"
Console : [20:35:39 WARN]: org.apache.commons.lang.UnhandledException: Plugin Statistics v1.2.4 generated an exception while executing task 303141
Console :       at org.bukkit.craftbukkit.v1_8_R3.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:56)
Console :       at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
Console :       at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
Console :       at java.lang.Thread.run(Thread.java:745)
Console : Caused by: java.lang.NullPointerException
Console :       at com.wolvencraft.yasp.session.OnlineSession.killedCreature(OnlineSession.java:242)
Console :       at com.wolvencraft.yasp.listeners.handlers.DeathHandler$MonsterDeath.run(DeathHandler.java:170)
Console :       at org.bukkit.craftbukkit.v1_8_R3.scheduler.CraftTask.run(CraftTask.java:71)
Console :       at org.bukkit.craftbukkit.v1_8_R3.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:53)
Console :       ... 3 more

Please provide any additional information below. (Plugin/Portal Version, Server Version, PHP Version. MySQL Version)
mysql  Ver 15.1 Distrib 10.0.22-MariaDB, for debian-linux-gnu (x86_64) using readline 5.2