Error on Spigot 1.11.2

[lss233]

Server version: 1.11.2-R0.1-SNAPSHOT
logs:

[20:21:39] [Server thread/WARN]: [ChopTreeW] Task #723 for ChopTreeW v1.6 generated an exception
java.lang.NoSuchFieldError: DIG_WOOD
	at me.crafter.mc.choptreew.ChopTask.chop(ChopTask.java:60) ~[?:?]
	at me.crafter.mc.choptreew.ChopTask.run(ChopTask.java:43) ~[?:?]
	at org.bukkit.craftbukkit.v1_11_R1.scheduler.CraftTask.run(CraftTask.java:71) ~[p13-v2-spigot-1.11.2.jar:git-Spigot-7d78b81-e2a288c]
	at org.bukkit.craftbukkit.v1_11_R1.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:353) [p13-v2-spigot-1.11.2.jar:git-Spigot-7d78b81-e2a288c]
	at net.minecraft.server.v1_11_R1.MinecraftServer.D(MinecraftServer.java:730) [p13-v2-spigot-1.11.2.jar:git-Spigot-7d78b81-e2a288c]
	at net.minecraft.server.v1_11_R1.DedicatedServer.D(DedicatedServer.java:399) [p13-v2-spigot-1.11.2.jar:git-Spigot-7d78b81-e2a288c]
	at net.minecraft.server.v1_11_R1.MinecraftServer.C(MinecraftServer.java:675) [p13-v2-spigot-1.11.2.jar:git-Spigot-7d78b81-e2a288c]
	at net.minecraft.server.v1_11_R1.MinecraftServer.run(MinecraftServer.java:574) [p13-v2-spigot-1.11.2.jar:git-Spigot-7d78b81-e2a288c]
	at java.lang.Thread.run(Thread.java:745) [?:1.8.0_121]
[20:21:39] [Server thread/WARN]: [ChopTreeW] Task #723 for ChopTreeW v1.6 generated an exception
java.lang.NoSuchFieldError: DIG_GRASS
	at me.crafter.mc.choptreew.ChopTask.chop(ChopTask.java:74) ~[?:?]
	at me.crafter.mc.choptreew.ChopTask.run(ChopTask.java:43) ~[?:?]
	at org.bukkit.craftbukkit.v1_11_R1.scheduler.CraftTask.run(CraftTask.java:71) ~[p13-v2-spigot-1.11.2.jar:git-Spigot-7d78b81-e2a288c]
	at org.bukkit.craftbukkit.v1_11_R1.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:353) [p13-v2-spigot-1.11.2.jar:git-Spigot-7d78b81-e2a288c]
	at net.minecraft.server.v1_11_R1.MinecraftServer.D(MinecraftServer.java:730) [p13-v2-spigot-1.11.2.jar:git-Spigot-7d78b81-e2a288c]
	at net.minecraft.server.v1_11_R1.DedicatedServer.D(DedicatedServer.java:399) [p13-v2-spigot-1.11.2.jar:git-Spigot-7d78b81-e2a288c]
	at net.minecraft.server.v1_11_R1.MinecraftServer.C(MinecraftServer.java:675) [p13-v2-spigot-1.11.2.jar:git-Spigot-7d78b81-e2a288c]
	at net.minecraft.server.v1_11_R1.MinecraftServer.run(MinecraftServer.java:574) [p13-v2-spigot-1.11.2.jar:git-Spigot-7d78b81-e2a288c]
	at java.lang.Thread.run(Thread.java:745) [?:1.8.0_121]