Bukkit

Command used (same as example on wiki):
anvil_gui:
command: /anvil_gui
type: ANVIL_GUI
anvil_title: '&eMyCommand &6ANVIL'
anvil_slot_text: write here
anvil_left_item: "BOOK:2:true:Write Here your lore;Line 2"
anvil_commands:
- $text$ $player, you typed $output
- /broadcast $output
- '%openiconmenu%/iconmenu $output'



Console error:

[22:15:41] [Server thread/INFO]: BR_Centauri issued server command: /anvil_gui[22:15:41] [Server thread/INFO]: BR_Centauri issued server command: /anvil_gui[22:15:41] [Server thread/ERROR]: Could not pass event PlayerCommandPreprocessEvent to MyCommand v5.7.2java.lang.ExceptionInInitializerError: null at it.emmerrei.mycommand.utilities.anvilgui.AnvilGUI$Builder.open(AnvilGUI.java:489) ~[MyCommand.jar:?] at it.emmerrei.mycommand.utilities.anvilgui.CreateAndOpen.CreateGUI(CreateAndOpen.java:201) ~[MyCommand.jar:?] at it.emmerrei.mycommand.execute.DispatchCommands.ExecuteMyCommandCommands(DispatchCommands.java:476) ~[MyCommand.jar:?] at it.emmerrei.mycommand.listener.PreprocessEvent.onPlayerCommandPreprocess(PreprocessEvent.java:283) ~[MyCommand.jar:?] at com.destroystokyo.paper.event.executor.asm.generated.GeneratedEventExecutor228.execute(Unknown Source) ~[?:?] at org.bukkit.plugin.EventExecutor.lambda$create$1(EventExecutor.java:69) ~[patched_1.17.1.jar:git-Paper-409] at co.aikar.timings.TimedEventExecutor.execute(TimedEventExecutor.java:80) ~[patched_1.17.1.jar:git-Paper-409] at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:70) ~[patched_1.17.1.jar:git-Paper-409] at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:628) ~[patched_1.17.1.jar:git-Paper-409] at net.minecraft.server.network.ServerGamePacketListenerImpl.handleCommand(ServerGamePacketListenerImpl.java:2254) ~[app:?] at net.minecraft.server.network.ServerGamePacketListenerImpl.handleChat(ServerGamePacketListenerImpl.java:2073) ~[app:?] at net.minecraft.server.network.ServerGamePacketListenerImpl.handleChat(ServerGamePacketListenerImpl.java:2054) ~[app:?] at net.minecraft.network.protocol.game.ServerboundChatPacket.handle(ServerboundChatPacket.java:46) ~[app:?] at net.minecraft.network.protocol.game.ServerboundChatPacket.a(ServerboundChatPacket.java:6) ~[app:?] at net.minecraft.network.protocol.PacketUtils.lambda$ensureRunningOnSameThread$1(PacketUtils.java:56) ~[app:?] at net.minecraft.server.TickTask.run(TickTask.java:18) ~[patched_1.17.1.jar:git-Paper-409] at net.minecraft.util.thread.BlockableEventLoop.doRunTask(BlockableEventLoop.java:149) ~[app:?] at net.minecraft.util.thread.ReentrantBlockableEventLoop.doRunTask(ReentrantBlockableEventLoop.java:23) ~[app:?] at net.minecraft.server.MinecraftServer.doRunTask(MinecraftServer.java:1426) ~[patched_1.17.1.jar:git-Paper-409] at net.minecraft.server.MinecraftServer.executeTask(MinecraftServer.java:192) ~[patched_1.17.1.jar:git-Paper-409] at net.minecraft.util.thread.BlockableEventLoop.pollTask(BlockableEventLoop.java:122) ~[app:?] at net.minecraft.server.MinecraftServer.pollTaskInternal(MinecraftServer.java:1404) ~[patched_1.17.1.jar:git-Paper-409] at net.minecraft.server.MinecraftServer.pollTask(MinecraftServer.java:1397) ~[patched_1.17.1.jar:git-Paper-409] at net.minecraft.util.thread.BlockableEventLoop.managedBlock(BlockableEventLoop.java:132) ~[app:?] at net.minecraft.server.MinecraftServer.waitUntilNextTick(MinecraftServer.java:1375) ~[patched_1.17.1.jar:git-Paper-409] at net.minecraft.server.MinecraftServer.runServer(MinecraftServer.java:1286) ~[patched_1.17.1.jar:git-Paper-409] at net.minecraft.server.MinecraftServer.lambda$spin$0(MinecraftServer.java:319) ~[patched_1.17.1.jar:git-Paper-409] at java.lang.Thread.run(Thread.java:833) ~[?:?]Caused by: java.lang.IllegalStateException: AnvilGUI does not support server version "1_17_R1" at it.emmerrei.mycommand.utilities.anvilgui.VersionMatcher.match(VersionMatcher.java:26) ~[MyCommand.jar:?] at it.emmerrei.mycommand.utilities.anvilgui.AnvilGUI.<clinit>(AnvilGUI.java:33) ~[MyCommand.jar:?] ... 28 moreCaused by: java.lang.ClassNotFoundException: it.emmerrei.mycommand.utilities.anvilgui.versions.Wrapper1_17_R1 at org.bukkit.plugin.java.PluginClassLoader.loadClass0(PluginClassLoader.java:151) ~[patched_1.17.1.jar:git-Paper-409] at org.bukkit.plugin.java.PluginClassLoader.loadClass(PluginClassLoader.java:103) ~[patched_1.17.1.jar:git-Paper-409] at java.lang.ClassLoader.loadClass(ClassLoader.java:520) ~[?:?] at java.lang.Class.forName0(Native Method) ~[?:?] at java.lang.Class.forName(Class.java:375) ~[?:?] at it.emmerrei.mycommand.utilities.anvilgui.VersionMatcher.match(VersionMatcher.java:22) ~[MyCommand.jar:?] at it.emmerrei.mycommand.utilities.anvilgui.AnvilGUI.<clinit>(AnvilGUI.java:33) ~[MyCommand.jar:?] ... 28 more