Disease Bukkin Plugin Error

[13:34:56 WARN]: [Disease] Task #52 for Disease v1.6.1 generated an exception
java.lang.NoSuchFieldError: SMALL_SMOKE
        at com.hmmcrunchy.disease.Disease$1.run(Disease.java:1130) ~[?:?]
        at org.bukkit.craftbukkit.v1_8_R2.scheduler.CraftTask.run(CraftTask.java
:53) ~[craftbukkit-1.8.3.jar:git-Bukkit-e4ca2af]
        at org.bukkit.craftbukkit.v1_8_R2.scheduler.CraftScheduler.mainThreadHea
rtbeat(CraftScheduler.java:349) [craftbukkit-1.8.3.jar:git-Bukkit-e4ca2af]
        at net.minecraft.server.v1_8_R2.MinecraftServer.A(MinecraftServer.java:6
77) [craftbukkit-1.8.3.jar:git-Bukkit-e4ca2af]
        at net.minecraft.server.v1_8_R2.DedicatedServer.A(DedicatedServer.java:3
36) [craftbukkit-1.8.3.jar:git-Bukkit-e4ca2af]
        at net.minecraft.server.v1_8_R2.MinecraftServer.z(MinecraftServer.java:6
26) [craftbukkit-1.8.3.jar:git-Bukkit-e4ca2af]
        at net.minecraft.server.v1_8_R2.MinecraftServer.run(MinecraftServer.java
:534) [craftbukkit-1.8.3.jar:git-Bukkit-e4ca2af]