不知道为什么启动的时候总是出现这样的错误：
008-6-26 17:48:06 org.apache.catalina.core.StandardContext addApplicationListener
信息: The listener "flex.messaging.HttpFlexSession" is already configured for this context. The duplicate definition has been ignored.
**** MessageBrokerServlet failed to initialize due to runtime exception: flex.messaging.config.ConfigurationException: The services configuration root element must be 'services-config'.
    at flex.messaging.config.ServerConfigurationParser.parseTopLevelConfig(ServerConfigurationParser.java:82)
    at flex.messaging.config.AbstractConfigurationParser.parse(AbstractConfigurationParser.java:68)
    at flex.messaging.config.FlexConfigurationManager.getMessagingConfiguration(FlexConfigurationManager.java:79)
    at flex.messaging.MessageBrokerServlet.init(MessageBrokerServlet.java:100)
    at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1161)
    at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:981)

还有：
严重: Servlet /MusicPlayer threw load() exception
javax.servlet.UnavailableException: The services configuration root element must be 'services-config'.
    at flex.messaging.MessageBrokerServlet.init(MessageBrokerServlet.java:163)
    at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1161)
这是为什么呢？
网上找了有类似的，但是没有结果：http://topic.csdn.net/u/20080506/10/4606ceb1-d053-4da4-b4f0-9a0958854e6f.html
我写了好多个project来测试，就是这个project会出现这样的问题！
难道跟代码有关系吗？
出现以上那些问题之后：
我的remoteobject访问就会出现如下的错误：
[RPC Fault faultString="Send failed" faultCode="Client.Error.MessageSend" faultDetail="Channel.Connect.Failed error NetConnection.Call.Failed: HTTP: Status 404: url: 'http://localhost:8080/MusicPlayer/messagebroker/amf'"]
    at mx.rpc::AbstractInvoker/http://www.adobe.com/2006/flex/mx/internal::faultHandler()[E:\dev\3.0.x\frameworks\projects\rpc\src\mx\rpc\AbstractInvoker.as:216]
    at mx.rpc::Responder/fault()[E:\dev\3.0.x\frameworks\projects\rpc\src\mx\rpc\Responder.as:49]
    at mx.rpc::AsyncRequest/fault()[E:\dev\3.0.x\frameworks\projects\rpc\src\mx\rpc\AsyncRequest.as:103]
    at mx.messaging::ChannelSet/faultPendingSends()[E:\dev\3.0.x\frameworks\projects\rpc\src\mx\messaging\ChannelSet.as:1399]
    at mx.messaging::ChannelSet/channelFaultHandler()[E:\dev\3.0.x\frameworks\projects\rpc\src\mx\messaging\ChannelSet.as:935]
    at flash.events::EventDispatcher/dispatchEventFunction()
    at flash.events::EventDispatcher/dispatchEvent()
    at mx.messaging::Channel/connectFailed()[E:\dev\3.0.x\frameworks\projects\rpc\src\mx\messaging\Channel.as:997]
    at mx.messaging.channels::PollingChannel/connectFailed()[E:\dev\3.0.x\frameworks\projects\rpc\src\mx\messaging\channels\PollingChannel.as:354]
    at mx.messaging.channels::AMFChannel/statusHandler()[E:\dev\3.0.x\frameworks\projects\rpc\src\mx\messaging\channels\AMFChannel.as:369]
我已经修改了content root为project的名字了
不知道他们之间是否有关联？

你配置文件有问题

看一下Context root设置是否正确。