#17 Material error on 1.14

[21:24:25] [Server thread/INFO]: Linus122 issued server command: /generator
[21:24:25] [Server thread/ERROR]: null
org.bukkit.command.CommandException: Unhandled exception executing 'generator' in xyz.spaceio.AdvancedOreGen.Command.ShowGeneratorCmd(generator)
	at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:156) ~[spigot-1.14.4.jar:git-Spigot-1981d55-860b354]
	at org.bukkit.craftbukkit.v1_14_R1.CraftServer.dispatchCommand(CraftServer.java:710) ~[spigot-1.14.4.jar:git-Spigot-1981d55-860b354]
	at net.minecraft.server.v1_14_R1.PlayerConnection.handleCommand(PlayerConnection.java:1641) ~[spigot-1.14.4.jar:git-Spigot-1981d55-860b354]
	at net.minecraft.server.v1_14_R1.PlayerConnection.a(PlayerConnection.java:1481) ~[spigot-1.14.4.jar:git-Spigot-1981d55-860b354]
	at net.minecraft.server.v1_14_R1.PacketPlayInChat.a(PacketPlayInChat.java:47) ~[spigot-1.14.4.jar:git-Spigot-1981d55-860b354]
	at net.minecraft.server.v1_14_R1.PacketPlayInChat.a(PacketPlayInChat.java:1) ~[spigot-1.14.4.jar:git-Spigot-1981d55-860b354]
	at net.minecraft.server.v1_14_R1.PlayerConnectionUtils.lambda$0(PlayerConnectionUtils.java:19) ~[spigot-1.14.4.jar:git-Spigot-1981d55-860b354]
	at net.minecraft.server.v1_14_R1.TickTask.run(SourceFile:18) [spigot-1.14.4.jar:git-Spigot-1981d55-860b354]
	at net.minecraft.server.v1_14_R1.IAsyncTaskHandler.executeTask(SourceFile:144) [spigot-1.14.4.jar:git-Spigot-1981d55-860b354]
	at net.minecraft.server.v1_14_R1.IAsyncTaskHandlerReentrant.executeTask(SourceFile:23) [spigot-1.14.4.jar:git-Spigot-1981d55-860b354]
	at net.minecraft.server.v1_14_R1.IAsyncTaskHandler.executeNext(SourceFile:118) [spigot-1.14.4.jar:git-Spigot-1981d55-860b354]
	at net.minecraft.server.v1_14_R1.MinecraftServer.aX(MinecraftServer.java:908) [spigot-1.14.4.jar:git-Spigot-1981d55-860b354]
	at net.minecraft.server.v1_14_R1.MinecraftServer.executeNext(MinecraftServer.java:901) [spigot-1.14.4.jar:git-Spigot-1981d55-860b354]
	at net.minecraft.server.v1_14_R1.IAsyncTaskHandler.awaitTasks(SourceFile:127) [spigot-1.14.4.jar:git-Spigot-1981d55-860b354]
	at net.minecraft.server.v1_14_R1.MinecraftServer.sleepForTick(MinecraftServer.java:885) [spigot-1.14.4.jar:git-Spigot-1981d55-860b354]
	at net.minecraft.server.v1_14_R1.MinecraftServer.run(MinecraftServer.java:818) [spigot-1.14.4.jar:git-Spigot-1981d55-860b354]
	at java.lang.Thread.run(Thread.java:748) [?:1.8.0_171]
Caused by: java.lang.NoSuchFieldError: STAINED_GLASS_PANE
	at xyz.spaceio.AdvancedOreGen.GUI.DisplayGeneratorsGUI.buildGUI(DisplayGeneratorsGUI.java:73) ~[?:?]
	at xyz.spaceio.AdvancedOreGen.GUI.DisplayGeneratorsGUI.<init>(DisplayGeneratorsGUI.java:23) ~[?:?]
	at xyz.spaceio.AdvancedOreGen.Command.ShowGeneratorCmd.execute(ShowGeneratorCmd.java:39) ~[?:?]
	at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:149) ~[spigot-1.14.4.jar:git-Spigot-1981d55-860b354]
	... 16 more