CRAFTBOOK-2965 - Reported by aceyxx

[05:18:16] [Server thread/ERROR]: Error occurred while enabling CraftBook v3.8-SNAPSHOT:3728-e4bd4bc,master (Is it up to date?)
org.yaml.snakeyaml.constructor.ConstructorException: null; could not determine a constructor for the tag tag:yaml.org,2002:org.bukkit.craftbukkit.v1_7_R1.inventory.CraftItemStack; in 'reader', line 5, column 11:
- !!org.bukkit.craftbukkit.v1_7_R1 ...
^
at org.yaml.snakeyaml.constructor.SafeConstructor$ConstructUndefined.construct(SafeConstructor.java:477) ~[spigot-1.7.2-R0.3.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
at org.yaml.snakeyaml.constructor.BaseConstructor.constructObject(BaseConstructor.java:182) ~[spigot-1.7.2-R0.3.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
at org.yaml.snakeyaml.constructor.BaseConstructor.constructSequenceStep2(BaseConstructor.java:276) ~[spigot-1.7.2-R0.3.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
at org.yaml.snakeyaml.constructor.BaseConstructor.constructSequence(BaseConstructor.java:247) ~[spigot-1.7.2-R0.3.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
at org.yaml.snakeyaml.constructor.SafeConstructor$ConstructYamlSeq.construct(SafeConstructor.java:442) ~[spigot-1.7.2-R0.3.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
at org.yaml.snakeyaml.constructor.BaseConstructor.constructObject(BaseConstructor.java:182) ~[spigot-1.7.2-R0.3.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
at org.yaml.snakeyaml.constructor.BaseConstructor.constructMapping2ndStep(BaseConstructor.java:325) ~[spigot-1.7.2-R0.3.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
at org.yaml.snakeyaml.constructor.SafeConstructor.constructMapping2ndStep(SafeConstructor.java:145) ~[spigot-1.7.2-R0.3.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
at org.yaml.snakeyaml.constructor.BaseConstructor.constructMapping(BaseConstructor.java:306) ~[spigot-1.7.2-R0.3.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
at org.yaml.snakeyaml.constructor.SafeConstructor$ConstructYamlMap.construct(SafeConstructor.java:461) ~[spigot-1.7.2-R0.3.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
at org.yaml.snakeyaml.constructor.BaseConstructor.constructObject(BaseConstructor.java:182) ~[spigot-1.7.2-R0.3.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
at org.yaml.snakeyaml.constructor.BaseConstructor.constructMapping2ndStep(BaseConstructor.java:325) ~[spigot-1.7.2-R0.3.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
at org.yaml.snakeyaml.constructor.SafeConstructor.constructMapping2ndStep(SafeConstructor.java:145) ~[spigot-1.7.2-R0.3.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
at org.yaml.snakeyaml.constructor.BaseConstructor.constructMapping(BaseConstructor.java:306) ~[spigot-1.7.2-R0.3.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
at org.yaml.snakeyaml.constructor.SafeConstructor$ConstructYamlMap.construct(SafeConstructor.java:461) ~[spigot-1.7.2-R0.3.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
at org.yaml.snakeyaml.constructor.BaseConstructor.constructObject(BaseConstructor.java:182) ~[spigot-1.7.2-R0.3.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
at org.yaml.snakeyaml.constructor.BaseConstructor.constructMapping2ndStep(BaseConstructor.java:325) ~[spigot-1.7.2-R0.3.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
at org.yaml.snakeyaml.constructor.SafeConstructor.constructMapping2ndStep(SafeConstructor.java:145) ~[spigot-1.7.2-R0.3.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
at org.yaml.snakeyaml.constructor.BaseConstructor.constructMapping(BaseConstructor.java:306) ~[spigot-1.7.2-R0.3.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
at org.yaml.snakeyaml.constructor.SafeConstructor$ConstructYamlMap.construct(SafeConstructor.java:461) ~[spigot-1.7.2-R0.3.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
at org.yaml.snakeyaml.constructor.BaseConstructor.constructObject(BaseConstructor.java:182) ~[spigot-1.7.2-R0.3.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
at org.yaml.snakeyaml.constructor.BaseConstructor.constructDocument(BaseConstructor.java:141) ~[spigot-1.7.2-R0.3.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
at org.yaml.snakeyaml.constructor.BaseConstructor.getSingleData(BaseConstructor.java:127) ~[spigot-1.7.2-R0.3.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
at org.yaml.snakeyaml.Yaml.loadFromReader(Yaml.java:481) ~[spigot-1.7.2-R0.3.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
at org.yaml.snakeyaml.Yaml.load(Yaml.java:424) ~[spigot-1.7.2-R0.3.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
at com.sk89q.util.yaml.YAMLProcessor.load(YAMLProcessor.java:112) ~[?:?]
at com.sk89q.craftbook.util.persistent.YAMLPersistentStorage.open(YAMLPersistentStorage.java:32) ~[?:?]
at com.sk89q.craftbook.bukkit.CraftBookPlugin.onEnable(CraftBookPlugin.java:274) ~[?:?]
at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:250) ~[spigot-1.7.2-R0.3.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:350) [spigot-1.7.2-R0.3.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:390) [spigot-1.7.2-R0.3.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
at org.bukkit.craftbukkit.v1_7_R1.CraftServer.loadPlugin(CraftServer.java:460) [spigot-1.7.2-R0.3.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
at org.bukkit.craftbukkit.v1_7_R1.CraftServer.enablePlugins(CraftServer.java:380) [spigot-1.7.2-R0.3.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
at net.minecraft.server.v1_7_R1.MinecraftServer.m(MinecraftServer.java:348) [spigot-1.7.2-R0.3.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
at net.minecraft.server.v1_7_R1.MinecraftServer.g(MinecraftServer.java:325) [spigot-1.7.2-R0.3.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
at net.minecraft.server.v1_7_R1.MinecraftServer.a(MinecraftServer.java:281) [spigot-1.7.2-R0.3.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
at net.minecraft.server.v1_7_R1.DedicatedServer.init(DedicatedServer.java:186) [spigot-1.7.2-R0.3.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
at net.minecraft.server.v1_7_R1.MinecraftServer.run(MinecraftServer.java:437) [spigot-1.7.2-R0.3.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
at net.minecraft.server.v1_7_R1.ThreadServerApplication.run(SourceFile:617) [spigot-1.7.2-R0.3.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]

Comment by me4502

Please pastebin your persistent.yml file, it appears it has been corrupted.