simplepets error (can't load)

[10:48:10] [Server thread/INFO]: [SimplePets] Enabling SimplePets v3.9
[10:48:10] [Server thread/INFO]: SimplePets >> Notice: Your Version of SimpleAPI is OutOfDate, Please update SimpleAPI https://www.spigotmc.org/resources/24671/
[10:48:10] [Server thread/INFO]: Disabling SimplePets...
[10:48:10] [Server thread/ERROR]: Error occurred while enabling SimplePets v3.9 (Is it up to date?)
java.lang.NullPointerException: null
	at simplepets.brainsynder.PetCore.onDisable(PetCore.java:334) ~[SimplePets.jar:?]
	at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:266) ~[spigot-1.12.2-R0.1-SNAPSHOT.jar:git-Spigot-7862817-bd30843]
	at simplepets.brainsynder.PetCore.onEnable(PetCore.java:88) ~[SimplePets.jar:?]
	at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:264) ~[spigot-1.12.2-R0.1-SNAPSHOT.jar:git-Spigot-7862817-bd30843]
	at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:337) [spigot-1.12.2-R0.1-SNAPSHOT.jar:git-Spigot-7862817-bd30843]
	at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:403) [spigot-1.12.2-R0.1-SNAPSHOT.jar:git-Spigot-7862817-bd30843]
	at org.bukkit.craftbukkit.v1_12_R1.CraftServer.enablePlugin(CraftServer.java:381) [spigot-1.12.2-R0.1-SNAPSHOT.jar:git-Spigot-7862817-bd30843]
	at org.bukkit.craftbukkit.v1_12_R1.CraftServer.enablePlugins(CraftServer.java:330) [spigot-1.12.2-R0.1-SNAPSHOT.jar:git-Spigot-7862817-bd30843]
	at net.minecraft.server.v1_12_R1.MinecraftServer.t(MinecraftServer.java:422) [spigot-1.12.2-R0.1-SNAPSHOT.jar:git-Spigot-7862817-bd30843]
	at net.minecraft.server.v1_12_R1.MinecraftServer.l(MinecraftServer.java:383) [spigot-1.12.2-R0.1-SNAPSHOT.jar:git-Spigot-7862817-bd30843]
	at net.minecraft.server.v1_12_R1.MinecraftServer.a(MinecraftServer.java:338) [spigot-1.12.2-R0.1-SNAPSHOT.jar:git-Spigot-7862817-bd30843]
	at net.minecraft.server.v1_12_R1.DedicatedServer.init(DedicatedServer.java:272) [spigot-1.12.2-R0.1-SNAPSHOT.jar:git-Spigot-7862817-bd30843]
	at net.minecraft.server.v1_12_R1.MinecraftServer.run(MinecraftServer.java:545) [spigot-1.12.2-R0.1-SNAPSHOT.jar:git-Spigot-7862817-bd30843]
	at java.lang.Thread.run(Thread.java:748) [?:1.8.0_151]