denizen error

[WARNING] .... java.lang.NoSuchMethodError: net/citizensnpcs/api/npc/NPC.getOrAddTrait(Ljava/lang/Class;)Lnet/citizensnpcs/api/trait/Trait; (loaded from file:/home/gs-41623/plugins/Citizens-2.0.26-b1802(1).jar by PluginClassLoader{plugin=Citizens v2.0.26-SNAPSHOT (build 1802), pluginEnabled=true, url=plugins/Citizens-2.0.26-b1802(1).jar}) called from class com.denizenscript.denizen.utilities.command.NPCCommandHandler (loaded from file:/home/gs-41623/plugins/Denizen-1.1.9-b1726-REL.jar by PluginClassLoader{plugin=Denizen v1.1.9-SNAPSHOT (build 1726-REL), pluginEnabled=false, url=plugins/Denizen-1.1.9-b1726-REL.jar}).

[WARNING] .... at com.denizenscript.denizen.utilities.command.NPCCommandHandler.sitting(NPCCommandHandler.java:322)

[WARNING] .... at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

[WARNING] .... at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)

[WARNING] .... at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

[WARNING] .... at java.lang.reflect.Method.invoke(Method.java:498)

[WARNING] .... at net.citizensnpcs.api.command.CommandManager.executeMethod(CommandManager.java:159)

[WARNING] .... at net.citizensnpcs.api.command.CommandManager.execute(CommandManager.java:91)

[WARNING] .... at net.citizensnpcs.api.command.CommandManager.executeSafe(CommandManager.java:187)

[WARNING] .... at net.citizensnpcs.Citizens.onCommand(Citizens.java:263)

[WARNING] .... at org.bukkit.command.PluginCommand.execute(PluginCommand.java:45)

[WARNING] .... at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:159)

[WARNING] .... at org.bukkit.craftbukkit.v1_15_R1.CraftServer.dispatchCommand(CraftServer.java:761)

[WARNING] .... at net.minecraft.server.v1_15_R1.PlayerConnection.handleCommand(PlayerConnection.java:1866)

[WARNING] .... at net.minecraft.server.v1_15_R1.PlayerConnection.a(PlayerConnection.java:1674)

[WARNING] .... at net.minecraft.server.v1_15_R1.PacketPlayInChat.a(PacketPlayInChat.java:47)

[WARNING] .... at net.minecraft.server.v1_15_R1.PacketPlayInChat.a(PacketPlayInChat.java:5)

[WARNING] .... at net.minecraft.server.v1_15_R1.PlayerConnectionUtils.lambda$ensureMainThread$0(PlayerConnectionUtils.java:23)

[WARNING] .... at net.minecraft.server.v1_15_R1.PlayerConnectionUtils$$Lambda$6014/0x00000000bd18d600.run(Unknown Source)

[WARNING] .... at net.minecraft.server.v1_15_R1.TickTask.run(SourceFile:18)

[WARNING] .... at net.minecraft.server.v1_15_R1.IAsyncTaskHandler.executeTask(IAsyncTaskHandler.java:136)

[WARNING] .... at net.minecraft.server.v1_15_R1.IAsyncTaskHandlerReentrant.executeTask(SourceFile:23)

[WARNING] .... at net.minecraft.server.v1_15_R1.IAsyncTaskHandler.executeNext(IAsyncTaskHandler.java:109)

[WARNING] .... at net.minecraft.server.v1_15_R1.MinecraftServer.ba(MinecraftServer.java:1105)

[WARNING] .... at net.minecraft.server.v1_15_R1.MinecraftServer.executeNext(MinecraftServer.java:1098)

[WARNING] .... at net.minecraft.server.v1_15_R1.IAsyncTaskHandler.awaitTasks(IAsyncTaskHandler.java:119)

[WARNING] .... at net.minecraft.server.v1_15_R1.MinecraftServer.sleepForTick(MinecraftServer.java:1059)

[WARNING] .... at net.minecraft.server.v1_15_R1.MinecraftServer.run(MinecraftServer.java:974)

[WARNING] .... at java.lang.Thread.run(Thread.java:823)