pet remove error

[19:43:37] [Craft Scheduler Thread - 106/WARN]: [SimplePets] Plugin SimplePets v4.0 generated an exception while executing task 2326283
java.lang.NullPointerException: null
	at simplepets.brainsynder.player.PetOwner.removePet(PetOwner.java:263) ~[SimplePets.jar:?]
	at simplepets.brainsynder.listeners.MainListeners$6.run(MainListeners.java:284) ~[SimplePets.jar:?]
	at org.bukkit.craftbukkit.v1_12_R1.scheduler.CraftTask.run(CraftTask.java:76) ~[spigot-1.12.2-R0.1-SNAPSHOT.jar:git-Spigot-642f6d2-ab13683]
	at org.bukkit.craftbukkit.v1_12_R1.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:52) [spigot-1.12.2-R0.1-SNAPSHOT.jar:git-Spigot-642f6d2-ab13683]
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [?:1.8.0_171]
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [?:1.8.0_171]
	at java.lang.Thread.run(Thread.java:748) [?:1.8.0_171]