嵌入式ApacheDS在示例模式文件上抛出LdapNoSuchAttributeException

如何解决嵌入式ApacheDS在示例模式文件上抛出LdapNoSuchAttributeException

我已经配置了嵌入式ApacheDS实例，并且正在尝试使用最小的LDIF配置使其运行。我从ApacheDS jar文件中包含的示例开始，但是遇到了LdapNoSuchAttributeException异常。

这是示例LDIF文件：

version: 1
dn: ou=schema
createtimestamp: 20090818022726Z
ou: schema
entrycsn: 20090818052725.311000Z#000000#000#000000
objectclass: organizationalUnit
objectclass: top
creatorsname: uid=admin,ou=system

这是错误：

org.apache.directory.shared.ldap.exception.LdapNoSuchAttributeException: ERR_04269 ATTRIBUTE_TYPE for OID objectclass does not exist!
    at org.apache.directory.shared.ldap.schema.registries.DefaultAttributeTypeRegistry.lookup(DefaultAttributeTypeRegistry.java:291)
    at org.apache.directory.shared.ldap.schema.registries.DefaultAttributeTypeRegistry.lookup(DefaultAttributeTypeRegistry.java:47)
    at org.apache.directory.shared.ldap.schema.manager.impl.DefaultSchemaManager.lookupAttributeTypeRegistry(DefaultSchemaManager.java:1457)
    at org.apache.directory.server.core.partition.avl.AvlStore.init(AvlStore.java:705)
    at org.apache.directory.server.core.partition.avl.AvlPartition.doInit(AvlPartition.java:159)
    at org.apache.directory.server.core.partition.AbstractPartition.initialize(AbstractPartition.java:65)
    at org.apache.directory.server.core.partition.ldif.LdifPartition.doInit(LdifPartition.java:163)
    at org.apache.directory.server.core.partition.AbstractPartition.initialize(AbstractPartition.java:65)
    at org.apache.directory.server.core.schema.SchemaPartition.doInit(SchemaPartition.java:229)
    at org.apache.directory.server.core.partition.AbstractPartition.initialize(AbstractPartition.java:65)
    at org.apache.directory.server.core.DefaultDirectoryService.initialize(DefaultDirectoryService.java:1426)
    at org.apache.directory.server.core.DefaultDirectoryService.startup(DefaultDirectoryService.java:907)

有人可以告诉我是什么导致此特定错误吗？