Can Someone plz help?

My friends starts his server and it says this
2013-02-17 00-39
=============================== GM ERROR LOG ===============================
= ERROR REPORT START - 2.0 (2.9.6) (Phoenix) =

java.lang.IllegalArgumentException: The following file couldn't pass on Parser.
plugins\GroupManager\worlds\world\groups.yml
at org.anjocaido.groupmanager.dataholder.WorldDataHolder.loadGroups(WorldDataHolder.java:497)
at org.anjocaido.groupmanager.dataholder.WorldDataHolder.loadGroups(WorldDataHolder.java:417)
at org.anjocaido.groupmanager.dataholder.worlds.WorldsHolder.loadWorld(WorldsHolder.java:629)
at org.anjocaido.groupmanager.dataholder.worlds.WorldsHolder.loadWorld(WorldsHolder.java:591)
at org.anjocaido.groupmanager.dataholder.worlds.WorldsHolder.initialWorldLoading(WorldsHolder.java:88)
at org.anjocaido.groupmanager.dataholder.worlds.WorldsHolder.initialLoad(WorldsHolder.java:78)
at org.anjocaido.groupmanager.dataholder.worlds.WorldsHolder.resetWorldsHolder(WorldsHolder.java:70)
at org.anjocaido.groupmanager.dataholder.worlds.WorldsHolder.<init>(WorldsHolder.java:59)
at org.anjocaido.groupmanager.GroupManager.onEnable(GroupManager.java:163)
at org.anjocaido.groupmanager.GroupManager.onEnable(GroupManager.java:87)
at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:217)
at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:457)
at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:381)
at org.bukkit.craftbukkit.v1_4_R1.CraftServer.loadPlugin(CraftServer.java:282)
at org.bukkit.craftbukkit.v1_4_R1.CraftServer.enablePlugins(CraftServer.java:264)
at net.minecraft.server.v1_4_R1.MinecraftServer.j(MinecraftServer.java:321)
at net.minecraft.server.v1_4_R1.MinecraftServer.e(MinecraftServer.java:300)
at net.minecraft.server.v1_4_R1.MinecraftServer.a(MinecraftServer.java:259)
at net.minecraft.server.v1_4_R1.DedicatedServer.init(DedicatedServer.java:149)
at net.minecraft.server.v1_4_R1.MinecraftServer.run(MinecraftServer.java:399)
at net.minecraft.server.v1_4_R1.ThreadServerApplication.run(SourceFile:849)
Caused by: while scanning for the next token
found character '\t' that cannot start any token
in "<reader>", line 41, column 1:
- builder
^

at org.yaml.snakeyaml.scanner.ScannerImpl.fetchMoreTokens(ScannerImpl.java:358)
at org.yaml.snakeyaml.scanner.ScannerImpl.checkToken(ScannerImpl.java:179)
at org.yaml.snakeyaml.parser.ParserImpl$ParseBlockMappingValue.produce(ParserImpl.java:591)
at org.yaml.snakeyaml.parser.ParserImpl.peekEvent(ParserImpl.java:161)
at org.yaml.snakeyaml.parser.ParserImpl.checkEvent(ParserImpl.java:146)
at org.yaml.snakeyaml.composer.Composer.composeNode(Composer.java:133)
at org.yaml.snakeyaml.composer.Composer.composeMappingNode(Composer.java:237)
at org.yaml.snakeyaml.composer.Composer.composeNode(Composer.java:160)
at org.yaml.snakeyaml.composer.Composer.composeMappingNode(Composer.java:237)
at org.yaml.snakeyaml.composer.Composer.composeNode(Composer.java:160)
at org.yaml.snakeyaml.composer.Composer.composeMappingNode(Composer.java:237)
at org.yaml.snakeyaml.composer.Composer.composeNode(Composer.java:160)
at org.yaml.snakeyaml.composer.Composer.composeDocument(Composer.java:123)
at org.yaml.snakeyaml.composer.Composer.getSingleNode(Composer.java:106)
at org.yaml.snakeyaml.constructor.BaseConstructor.getSingleData(BaseConstructor.java:121)
at org.yaml.snakeyaml.Yaml.loadFromReader(Yaml.java:480)
at org.yaml.snakeyaml.Yaml.load(Yaml.java:423)
at org.anjocaido.groupmanager.dataholder.WorldDataHolder.loadGroups(WorldDataHolder.java:492)
... 20 more

============================================================================
Can you help?