AreaShop 1.11 Error

[01:22:03 ERROR]: Error occurred while enabling AreaShop v2.3.2#CUSTOM (Is it up to date?)
java.lang.StringIndexOutOfBoundsException: String index out of range: -1
        at java.lang.String.substring(Unknown Source) ~[?:1.8.0_111]
        at me.wiefferink.areashop.AreaShop.onEnable(AreaShop.java:166) ~[?:?]
        at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:271) ~[spigot-1.11.jar:git-Spigot-f19bb2c-2b7808f]
        at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:337) [spigot-1.11.jar:git-Spigot-f19bb2c-2b7808f]
        at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:405) [spigot-1.11.jar:git-Spigot-f19bb2c-2b7808f]
        at org.bukkit.craftbukkit.v1_11_R1.CraftServer.enablePlugin(CraftServer.java:375) [spigot-1.11.jar:git-Spigot-f19bb2c-2b7808f]
        at org.bukkit.craftbukkit.v1_11_R1.CraftServer.enablePlugins(CraftServer.java:325) [spigot-1.11.jar:git-Spigot-f19bb2c-2b7808f]
        at net.minecraft.server.v1_11_R1.MinecraftServer.t(MinecraftServer.java:419) [spigot-1.11.jar:git-Spigot-f19bb2c-2b7808f]
        at net.minecraft.server.v1_11_R1.MinecraftServer.l(MinecraftServer.java:380) [spigot-1.11.jar:git-Spigot-f19bb2c-2b7808f]
        at net.minecraft.server.v1_11_R1.MinecraftServer.a(MinecraftServer.java:335) [spigot-1.11.jar:git-Spigot-f19bb2c-2b7808f]
        at net.minecraft.server.v1_11_R1.DedicatedServer.init(DedicatedServer.java:272) [spigot-1.11.jar:git-Spigot-f19bb2c-2b7808f]
        at net.minecraft.server.v1_11_R1.MinecraftServer.run(MinecraftServer.java:542) [spigot-1.11.jar:git-Spigot-f19bb2c-2b7808f]
        at java.lang.Thread.run(Unknown Source) [?:1.8.0_111]