引用web service时，出现无法识别的配置节点applicationSettings

昨天把项目部署到正式环境时，原来引用web service,在web.config中的节点，出现无法识别的配置节点<applicationSettings>的问题 

ApplicationSetting 节点的内容：

<applicationSettings>
  <TrafficPlanUI.Properties.Settings>
    <setting name="TrafficPlanUI_WebReference_UserAdminService" serializeAs="String">
      <value>http://10.132.100.1:8989/Jws/UserAdmin.jws</value>
    </setting>
  </TrafficPlanUI.Properties.Settings>
</applicationSettings>

仔细核对代码，原来在引用web service时, 配置节点configSections, 中的内容也添加了一行：

<configSections>
  <sectionGroup name="applicationSettings" type="System.Configuration.ApplicationSettingsGroup, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
    <section name="TrafficPlanUI.Properties.Settings" type="System.Configuration.ClientSettingsSection, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
  </sectionGroup>
</configSections>