How to get rid of "Warning as an Error" message

In the web config file, added the following add in Red under the compilers section for each compiler you have.

<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="WarnAsError" value="false"/>
</compiler>

</compilers>