Index 8 out of bounds for length 8

[WongIong]

[22:29:57 WARN]: [PictureLogin] Task #9091 for PictureLogin v1.6 generated an exception
java.lang.ArrayIndexOutOfBoundsException: Index 8 out of bounds for length 8
at me.itsnathang.picturelogin.config.ConfigManager.getMessage(ConfigManager.java:56) ~[PictureLogin-1.6.jar:?]
at me.itsnathang.picturelogin.util.PictureUtil.createPictureMessage(PictureUtil.java:75) ~[PictureLogin-1.6.jar:?]
at me.itsnathang.picturelogin.util.PictureWrapper.getMessage(PictureWrapper.java:41) ~[PictureLogin-1.6.jar:?]
at me.itsnathang.picturelogin.util.PictureWrapper.sendImage(PictureWrapper.java:48) ~[PictureLogin-1.6.jar:?]
at me.itsnathang.picturelogin.util.PictureWrapper.run(PictureWrapper.java:22) ~[PictureLogin-1.6.jar:?]
at org.bukkit.craftbukkit.v1_17_R1.scheduler.CraftTask.run(CraftTask.java:101) ~[patched_1.17.1.jar:git-Paper-411]
at org.bukkit.craftbukkit.v1_17_R1.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:483) ~[patched_1.17.1.jar:git-Paper-411]
at net.minecraft.server.MinecraftServer.tickChildren(MinecraftServer.java:1567) ~[patched_1.17.1.jar:git-Paper-411]
at net.minecraft.server.dedicated.DedicatedServer.tickChildren(DedicatedServer.java:490) ~[patched_1.17.1.jar:git-Paper-411]
at net.minecraft.server.MinecraftServer.tickServer(MinecraftServer.java:1483) ~[patched_1.17.1.jar:git-Paper-411]
at net.minecraft.server.MinecraftServer.runServer(MinecraftServer.java:1282) ~[patched_1.17.1.jar:git-Paper-411]
at net.minecraft.server.MinecraftServer.lambda$spin$0(MinecraftServer.java:319) ~[patched_1.17.1.jar:git-Paper-411]
at java.lang.Thread.run(Thread.java:833) ~[?:?]