vs2017 网站报错
原因Web.config是中下面这段：注释就可以了
<!--<system.codedom>
<compilers>
<compiler language="c#;cs;csharp" extension=".cs" warningLevel="4" type="Microsoft.CSharp.CSharpCodeProvider, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
<providerOption name="CompilerVersion" value="v4.5" />
<providerOption name="WarnAsError" value="false" />
</compiler>
</compilers>
</system.codedom>-->