I wanted to use the command //set or //fill as usual and this is the error code from the console:

An unexpected error while handling a WorldEdit commandAn unexpected error while handling a WorldEdit commandjava.lang.NoSuchMethodError: net.minecraft.server.v1_14_R1.IBlockState.d()Ljava/util/Collection; at com.sk89q.worldedit.bukkit.adapter.impl.Spigot_v1_14_R2.getProperties(Spigot_v1_14_R2.java:398) ~[?:?] at com.sk89q.worldedit.bukkit.BukkitBlockRegistry.getProperties(BukkitBlockRegistry.java:52) ~[?:?] at com.sk89q.worldedit.world.block.BlockType.lambda$getPropertyMap$1(BlockType.java:121) ~[?:?] at com.sk89q.worldedit.world.block.BlockType.updateField(BlockType.java:74) ~[?:?] at com.sk89q.worldedit.world.block.BlockType.getPropertyMap(BlockType.java:120) ~[?:?] at com.sk89q.worldedit.world.block.BlockType.getProperties(BlockType.java:130) ~[?:?] at com.sk89q.worldedit.world.block.BlockState.generateStateMap(BlockState.java:62) ~[?:?] at com.sk89q.worldedit.world.block.BlockType.lambda$getBlockStatesMap$0(BlockType.java:87) ~[?:?] at com.sk89q.worldedit.world.block.BlockType.updateField(BlockType.java:74) ~[?:?] at com.sk89q.worldedit.world.block.BlockType.getBlockStatesMap(BlockType.java:87) ~[?:?] at com.sk89q.worldedit.world.block.BlockType.lambda$getDefaultState$2(BlockType.java:154) ~[?:?] at com.sk89q.worldedit.world.block.BlockType.updateField(BlockType.java:74) ~[?:?] at com.sk89q.worldedit.world.block.BlockType.getDefaultState(BlockType.java:153) ~[?:?] at com.sk89q.worldedit.extension.factory.parser.DefaultBlockParser.parseLogic(DefaultBlockParser.java:327) ~[?:?] at com.sk89q.worldedit.extension.factory.parser.DefaultBlockParser.parseFromInput(DefaultBlockParser.java:88) ~[?:?] at com.sk89q.worldedit.extension.factory.parser.DefaultBlockParser.parseFromInput(DefaultBlockParser.java:61) ~[?:?] at com.sk89q.worldedit.internal.registry.AbstractFactory.parseFromInput(AbstractFactory.java:73) ~[?:?] at com.sk89q.worldedit.extension.factory.parser.pattern.SingleBlockPatternParser.parseFromInput(SingleBlockPatternParser.java:44) ~[?:?] at com.sk89q.worldedit.extension.factory.parser.pattern.SingleBlockPatternParser.parseFromInput(SingleBlockPatternParser.java:31) ~[?:?] at com.sk89q.worldedit.internal.registry.AbstractFactory.parseFromInput(AbstractFactory.java:73) ~[?:?] at com.sk89q.worldedit.command.argument.FactoryConverter.convert(FactoryConverter.java:89) ~[?:?] at org.enginehub.piston.impl.CommandParser.lambda$isAcceptedByTypeParsers$7(CommandParser.java:482) ~[?:?] at java.util.stream.MatchOps$1MatchSink.accept(MatchOps.java:90) ~[?:?] at java.util.Spliterators$IteratorSpliterator.tryAdvance(Spliterators.java:1812) ~[?:?] at java.util.stream.ReferencePipeline.forEachWithCancel(ReferencePipeline.java:127) ~[?:?] at java.util.stream.AbstractPipeline.copyIntoWithCancel(AbstractPipeline.java:502) ~[?:?] at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:488) ~[?:?] at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474) ~[?:?] at java.util.stream.MatchOps$MatchOp.evaluateSequential(MatchOps.java:230) ~[?:?] at java.util.stream.MatchOps$MatchOp.evaluateSequential(MatchOps.java:196) ~[?:?] at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234) ~[?:?] at java.util.stream.ReferencePipeline.anyMatch(ReferencePipeline.java:528) ~[?:?] at org.enginehub.piston.impl.CommandParser.isAcceptedByTypeParsers(CommandParser.java:477) ~[?:?] at org.enginehub.piston.impl.CommandParser.parseRegularArgument(CommandParser.java:414) ~[?:?] at org.enginehub.piston.impl.CommandParser.parse(CommandParser.java:326) ~[?:?] at org.enginehub.piston.impl.CommandManagerImpl.parse(CommandManagerImpl.java:230) ~[?:?] at org.enginehub.piston.CommandManager.execute(CommandManager.java:155) ~[?:?] at com.sk89q.worldedit.extension.platform.PlatformCommandManager.handleCommand(PlatformCommandManager.java:471) ~[?:?] at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:?] at jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:?] at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:?] at java.lang.reflect.Method.invoke(Method.java:566) ~[?:?] at com.sk89q.worldedit.util.eventbus.MethodEventHandler.dispatch(MethodEventHandler.java:58) ~[?:?] 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:328) ~[?:?] at com.sk89q.bukkit.util.DynamicPluginCommand.execute(DynamicPluginCommand.java:55) ~[?:?] at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:149) ~[craftbukkit.jar:git-Spigot-9de398a-9c887d4] at org.bukkit.craftbukkit.v1_14_R1.CraftServer.dispatchCommand(CraftServer.java:710) ~[craftbukkit.jar:git-Spigot-9de398a-9c887d4] at net.minecraft.server.v1_14_R1.PlayerConnection.handleCommand(PlayerConnection.java:1641) ~[craftbukkit.jar:git-Spigot-9de398a-9c887d4] at net.minecraft.server.v1_14_R1.PlayerConnection.a(PlayerConnection.java:1481) ~[craftbukkit.jar:git-Spigot-9de398a-9c887d4] at net.minecraft.server.v1_14_R1.PacketPlayInChat.a(PacketPlayInChat.java:47) ~[craftbukkit.jar:git-Spigot-9de398a-9c887d4] at net.minecraft.server.v1_14_R1.PacketPlayInChat.a(PacketPlayInChat.java:1) ~[craftbukkit.jar:git-Spigot-9de398a-9c887d4] at net.minecraft.server.v1_14_R1.PlayerConnectionUtils.lambda$0(PlayerConnectionUtils.java:19) ~[craftbukkit.jar:git-Spigot-9de398a-9c887d4] at net.minecraft.server.v1_14_R1.TickTask.run(SourceFile:18) [craftbukkit.jar:git-Spigot-9de398a-9c887d4] at net.minecraft.server.v1_14_R1.IAsyncTaskHandler.executeTask(SourceFile:144) [craftbukkit.jar:git-Spigot-9de398a-9c887d4] at net.minecraft.server.v1_14_R1.IAsyncTaskHandlerReentrant.executeTask(SourceFile:23) [craftbukkit.jar:git-Spigot-9de398a-9c887d4] at net.minecraft.server.v1_14_R1.IAsyncTaskHandler.executeNext(SourceFile:118) [craftbukkit.jar:git-Spigot-9de398a-9c887d4] at net.minecraft.server.v1_14_R1.MinecraftServer.aX(MinecraftServer.java:910) [craftbukkit.jar:git-Spigot-9de398a-9c887d4] at net.minecraft.server.v1_14_R1.MinecraftServer.executeNext(MinecraftServer.java:903) [craftbukkit.jar:git-Spigot-9de398a-9c887d4] at net.minecraft.server.v1_14_R1.IAsyncTaskHandler.awaitTasks(SourceFile:127) [craftbukkit.jar:git-Spigot-9de398a-9c887d4] at net.minecraft.server.v1_14_R1.MinecraftServer.sleepForTick(MinecraftServer.java:887) [craftbukkit.jar:git-Spigot-9de398a-9c887d4] at net.minecraft.server.v1_14_R1.MinecraftServer.run(MinecraftServer.java:820) [craftbukkit.jar:git-Spigot-9de398a-9c887d4] at java.lang.Thread.run(Thread.java:834) [?:?]