SQL Server数据库登陆时提示报错如图:

源错误 : 

行 135:        </roleManager>

行 136: </system.web>

行 137: <system.serviceModel>

行 138:        <extensions>

行 139:                <behaviorExtensions>

源文件 : C:/WINDOWS/Microsoft.NET/Framework/v2.0.50727/Config/machine.config    行 : 137

版本信息 :  Microsoft .NET Framework 版本 :2.0.50727.3053; ASP.NET 版本 :2.0.50727.3053

出现这个错误可能是机器重启的时候，配置文件中.NETFRAMEWORK3.0部分的控制运行配置并没有加进去，所以造成配置文件出错，这时只需要添加配置就可以了。

<sectionGroup name="system.serviceModel" type="System.ServiceModel.Configuration.ServiceModelSectionGroup, System.ServiceModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">  

<section name="behaviors" type="System.ServiceModel.Configuration.BehaviorsSection, System.ServiceModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/>  

<section name="bindings" type="System.ServiceModel.Configuration.BindingsSection, System.ServiceModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/>  

<section name="client" type="System.ServiceModel.Configuration.ClientSection, System.ServiceModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/>  

<section name="comContracts" type="System.ServiceModel.Configuration.ComContractsSection, System.ServiceModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/>  

<section name="commonBehaviors" type="System.ServiceModel.Configuration.CommonBehaviorsSection, System.ServiceModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" allowDefinition="MachineOnly" allowExeDefinition="MachineOnly"/>  

<section name="diagnostics" type="System.ServiceModel.Configuration.DiagnosticSection, System.ServiceModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/>  

<section name="extensions" type="System.ServiceModel.Configuration.ExtensionsSection, System.ServiceModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/>  

<section name="machineSettings" type="System.ServiceModel.Configuration.MachineSettingsSection, SMDiagnostics, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" allowDefinition="MachineOnly" allowExeDefinition="MachineOnly"/>  

<section name="serviceHostingEnvironment" type="System.ServiceModel.Configuration.ServiceHostingEnvironmentSection, System.ServiceModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/>  

<section name="services" type="System.ServiceModel.Configuration.ServicesSection, System.ServiceModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/>  

</sectionGroup>  

<sectionGroup name="system.serviceModel.activation" type="System.ServiceModel.Activation.Configuration.ServiceModelActivationSectionGroup, System.ServiceModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">  

<section name="diagnostics" type="System.ServiceModel.Activation.Configuration.DiagnosticSection, System.ServiceModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/>  

<section name="net.pipe" type="System.ServiceModel.Activation.Configuration.NetPipeSection, System.ServiceModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/>  

<section name="net.tcp" type="System.ServiceModel.Activation.Configuration.NetTcpSection, System.ServiceModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/>  

</sectionGroup>  

将以上内容添加到C:/WINDOWS/Microsoft.NET/Framework/v2.0.50727/Config/machine.config文件中的configSections之间就可以了。

重新打开SQL Server数据库测试数据库已经正常登陆，未再出现相关报错。