[21:57:33] [pool-3-thread-204/WARN]: Exception in thread "pool-3-thread-204"
[21:57:33] [pool-3-thread-204/WARN]: org.apache.commons.lang.UnhandledException: Plugin Shopkeepers v1.63 generated an exception while executing task 47904
	at org.bukkit.craftbukkit.v1_8_R3.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:56)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at java.lang.Thread.run(Thread.java:744)
Caused by: java.lang.NullPointerException: null key in entry: null=1
	at com.google.common.collect.CollectPreconditions.checkEntryNotNull(CollectPreconditions.java:31)
	at com.google.common.collect.ImmutableMap.entryOf(ImmutableMap.java:135)
	at com.google.common.collect.ImmutableMap$Builder.put(ImmutableMap.java:206)
	at org.bukkit.craftbukkit.v1_8_R3.inventory.CraftMetaItem.serializeEnchantments(CraftMetaItem.java:746)
	at org.bukkit.craftbukkit.v1_8_R3.inventory.CraftMetaItem.serialize(CraftMetaItem.java:703)
	at org.bukkit.craftbukkit.v1_8_R3.inventory.CraftMetaItem.serialize(CraftMetaItem.java:689)
	at org.bukkit.configuration.file.YamlRepresenter$RepresentConfigurationSerializable.representData(YamlRepresenter.java:33)
	at org.yaml.snakeyaml.representer.BaseRepresenter.representData(BaseRepresenter.java:94)
	at org.yaml.snakeyaml.representer.BaseRepresenter.representMapping(BaseRepresenter.java:156)
	at org.yaml.snakeyaml.representer.SafeRepresenter$RepresentMap.representData(SafeRepresenter.java:304)
	at org.bukkit.configuration.file.YamlRepresenter$RepresentConfigurationSerializable.representData(YamlRepresenter.java:35)
	at org.yaml.snakeyaml.representer.BaseRepresenter.representData(BaseRepresenter.java:94)
	at org.yaml.snakeyaml.representer.BaseRepresenter.representMapping(BaseRepresenter.java:156)
	at org.yaml.snakeyaml.representer.SafeRepresenter$RepresentMap.representData(SafeRepresenter.java:304)
	at org.bukkit.configuration.file.YamlRepresenter$RepresentConfigurationSection.representData(YamlRepresenter.java:23)
	at org.yaml.snakeyaml.representer.BaseRepresenter.representData(BaseRepresenter.java:94)
	at org.yaml.snakeyaml.representer.BaseRepresenter.representMapping(BaseRepresenter.java:156)
	at org.yaml.snakeyaml.representer.SafeRepresenter$RepresentMap.representData(SafeRepresenter.java:304)
	at org.bukkit.configuration.file.YamlRepresenter$RepresentConfigurationSection.representData(YamlRepresenter.java:23)
	at org.yaml.snakeyaml.representer.BaseRepresenter.representData(BaseRepresenter.java:94)
	at org.yaml.snakeyaml.representer.BaseRepresenter.representMapping(BaseRepresenter.java:156)
	at org.yaml.snakeyaml.representer.SafeRepresenter$RepresentMap.representData(SafeRepresenter.java:304)
	at org.bukkit.configuration.file.YamlRepresenter$RepresentConfigurationSection.representData(YamlRepresenter.java:23)
	at org.yaml.snakeyaml.representer.BaseRepresenter.representData(BaseRepresenter.java:94)
	at org.yaml.snakeyaml.representer.BaseRepresenter.representMapping(BaseRepresenter.java:156)
	at org.yaml.snakeyaml.representer.SafeRepresenter$RepresentMap.representData(SafeRepresenter.java:304)
	at org.yaml.snakeyaml.representer.BaseRepresenter.representData(BaseRepresenter.java:94)
	at org.yaml.snakeyaml.representer.BaseRepresenter.represent(BaseRepresenter.java:64)
	at org.yaml.snakeyaml.Yaml.dumpAll(Yaml.java:242)
	at org.yaml.snakeyaml.Yaml.dumpAll(Yaml.java:206)
	at org.yaml.snakeyaml.Yaml.dump(Yaml.java:181)
	at org.bukkit.configuration.file.YamlConfiguration.saveToString(YamlConfiguration.java:40)
	at com.nisovin.shopkeepers.ShopkeepersPlugin.saveDataToFile(ShopkeepersPlugin.java:1390)
	at com.nisovin.shopkeepers.ShopkeepersPlugin.access$1200(ShopkeepersPlugin.java:62)
	at com.nisovin.shopkeepers.ShopkeepersPlugin$11.run(ShopkeepersPlugin.java:1300)
	at org.bukkit.craftbukkit.v1_8_R3.scheduler.CraftTask.run(CraftTask.java:53)
	at org.bukkit.craftbukkit.v1_8_R3.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:53)
	... 3 more