Error occurs on .border(Element.of(ItemStack.of(ItemTypes.STAINED_GLASS_PANE, 1))) when opening GUI

error.txt

[20:33:15] [Server thread/ERROR] [Sponge]: Error occurred while executing command 'shop' for source EntityPlayerMP['Geometrically'/290, l='world', x=-49.84, y=65.00, z=246.24]: index (27) must be less than size (27)
java.lang.IndexOutOfBoundsException: index (27) must be less than size (27)
        at com.google.common.base.Preconditions.checkElementIndex(Preconditions.java:1177) ~[minecraft_server.1.12.2.jar:?]
        at com.google.common.base.Preconditions.checkElementIndex(Preconditions.java:1159) ~[minecraft_server.1.12.2.jar:?]
        at com.mcsimonflash.sponge.teslalibs.inventory.Layout$Builder.set(Layout.java:86) ~[Layout$Builder.class:?]
        at com.mcsimonflash.sponge.teslalibs.inventory.Layout$Builder.border(Layout.java:144) ~[Layout$Builder.class:?]
        at net.unhingednetwork.perks.command.ShopCommand.execute(ShopCommand.java:42) ~[ShopCommand.class:?]
        at org.spongepowered.api.command.spec.CommandSpec.process(CommandSpec.java:388) ~[CommandSpec.class:1.12.2-2655-7.1.0-BETA-3095]
        at org.spongepowered.api.command.dispatcher.SimpleDispatcher.process(SimpleDispatcher.java:341) ~[SimpleDispatcher.class:1.12.2-2655-7.1.0-BETA-3095]
        at org.spongepowered.common.command.SpongeCommandManager.process(SpongeCommandManager.java:328) [SpongeCommandManager.class:1.12.2-2655-7.1.0-BETA-3095]
        at net.minecraft.command.ServerCommandManager.func_71556_a(SourceFile:1083) [dh.class:?]
        at net.minecraft.network.NetHandlerPlayServer.func_147361_d(NetHandlerPlayServer.java:958) [pa.class:?]
        at net.minecraft.network.NetHandlerPlayServer.func_147354_a(NetHandlerPlayServer.java:937) [pa.class:?]
        at net.minecraft.network.play.client.CPacketChatMessage.func_148833_a(SourceFile:37) [la.class:?]
        at net.minecraft.network.play.client.CPacketChatMessage.func_148833_a(SourceFile:9) [la.class:?]
        at org.spongepowered.common.network.PacketUtil.onProcessPacket(PacketUtil.java:148) [PacketUtil.class:1.12.2-2655-7.1.0-BETA-3095]
        at net.minecraft.network.PacketThreadUtil$1.redirect$onProcessPacket$zlb000(SourceFile:539) [hv$1.class:?]
        at net.minecraft.network.PacketThreadUtil$1.run(SourceFile:13) [hv$1.class:?]
        at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) [?:1.8.0_161]
        at java.util.concurrent.FutureTask.run(Unknown Source) [?:1.8.0_161]
        at net.minecraft.util.Util.func_181617_a(SourceFile:46) [h.class:?]
        at org.spongepowered.common.SpongeImplHooks.onUtilRunTask(SpongeImplHooks.java:284) [SpongeImplHooks.class:1.12.2-2655-7.1.0-BETA-3095]
        at net.minecraft.server.MinecraftServer.redirect$onRun$zjg000(MinecraftServer.java:3975) [MinecraftServer.class:?]
        at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:721) [MinecraftServer.class:?]
        at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:396) [nz.class:?]
        at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:666) [MinecraftServer.class:?]
        at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:524) [MinecraftServer.class:?]
        at java.lang.Thread.run(Unknown Source) [?:1.8.0_161]
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