dissalow use of gui and add warning for folia.

nms/v1_21R1/src/main/kotlin/xyz/alexcrea/cuanvil/dependency/scheduler/FoliaScheduler.kt

@@ -6,7 +6,7 @@ import org.bukkit.entity.Entity
 import org.bukkit.plugin.Plugin
 import java.util.function.Consumer
 
-class PaperScheduler : TaskScheduler {
+class FoliaScheduler : TaskScheduler {
     override fun scheduleGlobally(plugin: Plugin, task: Runnable, time: Long): Any? {
         if(time < 1){
             return Bukkit.getGlobalRegionScheduler().run(
@@ -39,11 +39,11 @@ class PaperScheduler : TaskScheduler {
     }
 
     companion object {
-        fun isPaper(): Boolean {
+        fun isFolia(): Boolean {
             try {
-                Bukkit::class.java.getDeclaredMethod("getGlobalRegionScheduler")
+                Class.forName("io.papermc.paper.threadedregions.RegionizedServer")
                 return true
-            } catch (e: NoSuchMethodException) {
+            } catch (e: ClassNotFoundException) {
                 return false
             }
         }

src/main/kotlin/xyz/alexcrea/cuanvil/command/EditConfigExecutor.kt

@@ -5,6 +5,7 @@ import org.bukkit.command.Command
 import org.bukkit.command.CommandExecutor
 import org.bukkit.command.CommandSender
 import org.bukkit.entity.HumanEntity
+import xyz.alexcrea.cuanvil.dependency.DependencyManager
 import xyz.alexcrea.cuanvil.gui.config.MainConfigGui
 import xyz.alexcrea.cuanvil.gui.util.GuiGlobalActions
 
@@ -15,6 +16,15 @@ class EditConfigExecutor : CommandExecutor {
             sender.sendMessage(GuiGlobalActions.NO_EDIT_PERM)
             return false
         }
+        if(DependencyManager.isFolia){
+            sender.sendMessage("§cIt look like you are using Folia. Sadly Custom Anvil do not support Config gui for Folia.")
+            sender.sendMessage("§eIt is may come in a future version.")
+            sender.sendMessage("")
+            sender.sendMessage("§eCurrently you need to edit manually the config or copy from another server (spigot or better)")
+            sender.sendMessage("§eThen /anvilconfigreload after config file is edited")
+            return false
+        }
+
         if (sender !is HumanEntity) return false
         MainConfigGui.getInstance().show(sender)
 

src/main/kotlin/xyz/alexcrea/cuanvil/dependency/DependencyManager.kt

@@ -1,5 +1,6 @@
 package xyz.alexcrea.cuanvil.dependency
 
+import io.delilaheve.CustomAnvil
 import org.bukkit.Bukkit
 import org.bukkit.event.inventory.InventoryClickEvent
 import org.bukkit.event.inventory.PrepareAnvilEvent
@@ -8,11 +9,12 @@ import xyz.alexcrea.cuanvil.config.ConfigHolder
 import xyz.alexcrea.cuanvil.dependency.packet.PacketManager
 import xyz.alexcrea.cuanvil.dependency.packet.PacketManagerSelector
 import xyz.alexcrea.cuanvil.dependency.scheduler.BukkitScheduler
-import xyz.alexcrea.cuanvil.dependency.scheduler.PaperScheduler
+import xyz.alexcrea.cuanvil.dependency.scheduler.FoliaScheduler
 import xyz.alexcrea.cuanvil.dependency.scheduler.TaskScheduler
 
 object DependencyManager {
 
+    var isFolia: Boolean = false
     lateinit var scheduler: TaskScheduler
     lateinit var packetManager: PacketManager
     var enchantmentSquaredCompatibility: EnchantmentSquaredDependency? = null
@@ -23,9 +25,12 @@ object DependencyManager {
         val pluginManager = Bukkit.getPluginManager()
 
         // Bukkit or Paper scheduler ?
-        scheduler = if(PaperScheduler.isPaper()) PaperScheduler()
+        isFolia = FoliaScheduler.isFolia()
-        else BukkitScheduler()
+        scheduler = if(isFolia) {
+            CustomAnvil.instance.logger.info("Folia detected... Custom Anvil Folia support is experimental. issues are more likely to happens.")
 
+            FoliaScheduler()
+        } else BukkitScheduler()
 
         // Packet Manager
         val forceProtocolib = ConfigHolder.DEFAULT_CONFIG.config.getBoolean("force_protocolib", false)