2016-06-02

CS1056: Unexpected character '$'

When you get the message " CS1056: Unexpected character '$' " in runtime asp.net, it means that the front end file (html/aspx) is using a way of formatting strings which is called "string interpolation".
But to use string interpolation in your web frontend files you must put the following into your web.config file:

<system.codedom>
  <compilers>
    <compiler language="c#;cs;csharp" extension=".cs"
      type="Microsoft.CodeDom.Providers.DotNetCompilerPlatform.CSharpCodeProvider, Microsoft.CodeDom.Providers.DotNetCompilerPlatform, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"
      warningLevel="4" compilerOptions="/langversion:6 /nowarn:1659;1699;1701"/>
    <compiler language="vb;vbs;visualbasic;vbscript" extension=".vb"
      type="Microsoft.CodeDom.Providers.DotNetCompilerPlatform.VBCodeProvider, Microsoft.CodeDom.Providers.DotNetCompilerPlatform, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"
      warningLevel="4" compilerOptions="/langversion:14 /nowarn:41008 /define:_MYTYPE=\&quot;Web\&quot; /optionInfer+"/>
  </compilers>
</system.codedom>

Source:
http://stackoverflow.com/questions/30832659/string-interpolation-in-a-razor-view
 
Disclaimer:
The above worked for me, but may not work for all .NET Framework versions and/or ASP.NET versions.