Appears to be a problem with this line in ChunkUtils.java:
fChunkProvider = cWorldServer.findField(cChunkProviderServer);
[19:03:17 WARN]: [PowerNBT] Can't load ChunkUtils!
java.lang.RuntimeException: no such field
at me.dpohvar.powernbt.utils.ReflectionUtils$RefClass.findField(ReflectionUtils.java:431) ~[PowerNBT.jar:?]
at me.dpohvar.powernbt.utils.ReflectionUtils$RefClass.findField(ReflectionUtils.java:401) ~[PowerNBT.jar:?]
at me.dpohvar.powernbt.utils.ChunkUtils.<init>(ChunkUtils.java:50) [PowerNBT.jar:?]
at me.dpohvar.powernbt.utils.ChunkUtils.<clinit>(ChunkUtils.java:19) [PowerNBT.jar:?]
at me.dpohvar.powernbt.PowerNBT.initializeUtils(PowerNBT.java:137) [PowerNBT.jar:?]
at me.dpohvar.powernbt.PowerNBT.onEnable(PowerNBT.java:125) [PowerNBT.jar:?]
at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:292) [server.jar:git-Spigot-1480adb-8b61cc5]
at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:340) [server.jar:git-Spigot-1480adb-8b61cc5]
at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:405) [server.jar:git-Spigot-1480adb-8b61cc5]
at org.bukkit.craftbukkit.v1_9_R1.CraftServer.loadPlugin(CraftServer.java:361) [server.jar:git-Spigot-1480adb-8b61cc5]
at org.bukkit.craftbukkit.v1_9_R1.CraftServer.enablePlugins(CraftServer.java:321) [server.jar:git-Spigot-1480adb-8b61cc5]
at net.minecraft.server.v1_9_R1.MinecraftServer.t(MinecraftServer.java:411) [server.jar:git-Spigot-1480adb-8b61cc5]
at net.minecraft.server.v1_9_R1.MinecraftServer.l(MinecraftServer.java:376) [server.jar:git-Spigot-1480adb-8b61cc5]
at net.minecraft.server.v1_9_R1.MinecraftServer.a(MinecraftServer.java:331) [server.jar:git-Spigot-1480adb-8b61cc5]
at net.minecraft.server.v1_9_R1.DedicatedServer.init(DedicatedServer.java:269) [server.jar:git-Spigot-1480adb-8b61cc5]
at net.minecraft.server.v1_9_R1.MinecraftServer.run(MinecraftServer.java:527) [server.jar:git-Spigot-1480adb-8b61cc5]
at java.lang.Thread.run(Thread.java:745) [?:1.8.0_74]
Appears to be a problem with this line in ChunkUtils.java: fChunkProvider = cWorldServer.findField(cChunkProviderServer);