Возможно, ты ещё и не знаешь о том, что нельзя использовать /reload ?
Короче говоря: останови сервер -> удали старый WE -> засунь новый -> на всякий случай удали его конфиг -> запусти сервер -> проверяй
Если есть ошибки в консоли при запуске сервера или использовании команд, отправляй сюда.
Попробовал.
По поводу //undo ошибок нет, просто дропает все блоки в выделенном регионе.
А вот //regen выдаёт ошибку
[18:53:31 INFO]: Zorgling issued server command: //regen
[18:53:31 WARN]: Regeneration via adapter failed.
java.lang.RuntimeException: Old Chunk Storage is no longer supported.
at net.minecraft.server.v1_13_R2.WorldNBTStorage.createChunkLoader(WorldNBTStorage.java:89) ~[server.jar:git-Spigot-1a3504a-06534f2]
at net.minecraft.server.v1_13_R2.WorldServer.r(WorldServer.java:687) ~[server.jar:git-Spigot-1a3504a-06534f2]
at net.minecraft.server.v1_13_R2.WorldServer.init(WorldServer.java:72) ~[server.jar:git-Spigot-1a3504a-06534f2]
at com.sk89q.worldedit.bukkit.adapter.impl.Spigot_v1_13_R2_2.regenerate(Spigot_v1_13_R2_2.java:522) ~[?:?]
at com.sk89q.worldedit.bukkit.BukkitWorld.regenerate(BukkitWorld.java:216) ~[?:?]
at com.sk89q.worldedit.command.RegionCommands.regenerate(RegionCommands.java:431) ~[?:?]
at com.sk89q.worldedit.command.RegionCommandsRegistration.cmd$_regen(RegionCommandsRegistration.java:576) ~[?:?]
at org.enginehub.piston.CommandManager.execute(CommandManager.java:157) ~[?:?]
at com.sk89q.worldedit.extension.platform.PlatformCommandManager.handleCommand(PlatformCommandManager.java:497) ~[?:?]
at com.sk89q.worldedit.util.eventbus.MethodHandleEventHandler.dispatch(MethodHandleEventHandler.java:51) ~[?:?]
at com.sk89q.worldedit.util.eventbus.EventHandler.handleEvent(EventHandler.java:73) ~[?:?]
at com.sk89q.worldedit.util.eventbus.EventBus.dispatch(EventBus.java:193) ~[?:?]
at com.sk89q.worldedit.util.eventbus.EventBus.post(EventBus.java:181) ~[?:?]
at com.sk89q.worldedit.bukkit.WorldEditPlugin.onCommand(WorldEditPlugin.java:383) ~[?:?]
at com.sk89q.bukkit.util.DynamicPluginCommand.execute(DynamicPluginCommand.java:55) ~[?:?]
at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:141) ~[server.jar:git-Spigot-1a3504a-06534f2]
at org.bukkit.craftbukkit.v1_13_R2.CraftServer.dispatchCommand(CraftServer.java:704) ~[server.jar:git-Spigot-1a3504a-06534f2]
at net.minecraft.server.v1_13_R2.PlayerConnection.handleCommand(PlayerConnection.java:1621) ~[server.jar:git-Spigot-1a3504a-06534f2]
at net.minecraft.server.v1_13_R2.PlayerConnection.a(PlayerConnection.java:1461) ~[server.jar:git-Spigot-1a3504a-06534f2]
at net.minecraft.server.v1_13_R2.PacketPlayInChat.a(PacketPlayInChat.java:45) ~[server.jar:git-Spigot-1a3504a-06534f2]
at net.minecraft.server.v1_13_R2.PacketPlayInChat.a(PacketPlayInChat.java:1) ~[server.jar:git-Spigot-1a3504a-06534f2]
at net.minecraft.server.v1_13_R2.PlayerConnectionUtils.lambda$0(PlayerConnectionUtils.java:9) ~[server.jar:git-Spigot-1a3504a-06534f2]
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_312]
at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_312]
at net.minecraft.server.v1_13_R2.SystemUtils.a(SourceFile:199) [server.jar:git-Spigot-1a3504a-06534f2]
at net.minecraft.server.v1_13_R2.MinecraftServer.b(MinecraftServer.java:896) [server.jar:git-Spigot-1a3504a-06534f2]
at net.minecraft.server.v1_13_R2.DedicatedServer.b(DedicatedServer.java:417) [server.jar:git-Spigot-1a3504a-06534f2]
at net.minecraft.server.v1_13_R2.MinecraftServer.a(MinecraftServer.java:831) [server.jar:git-Spigot-1a3504a-06534f2]
at net.minecraft.server.v1_13_R2.MinecraftServer.run(MinecraftServer.java:729) [server.jar:git-Spigot-1a3504a-06534f2]
at java.lang.Thread.run(Thread.java:748) [?:1.8.0_312]