c# - The CodeDom provider type "Microsoft.CodeDom.Providers.DotNetCompilerPlatform.CSharpCodeProvider" could not be located

Question

It's a WebApi project using VS2015.

Step to reproduce:

1. Create an empty WebApi project
2. Change Build output path from "bin" to "binDebug"
3. Run

Everything is working perfectly until I changed Build Output path from "bin" to "binDebug" In fact, any Output path other than "bin" won't work.

One little additional thing is that, having another output path to anywhere would work as long as I left a build in "bin".

Please help providing solution to solve this. I guess that'll cost problem on actual deployment.

Answer 1

If your project has Roslyn references and you are deploying it on an IIS server, you might get unwanted errors on the website as many hosting providers still have not upgraded their servers and hence do not support Roslyn.

To resolve this issue, you will need to remove the Roslyn compiler from the project template. Removing Roslyn shouldn't affect your code's functionality. It worked fine for me and some other projects (C# 4.5.2) on which I worked.

Do the following steps:

1. Remove from following Nuget Packages using command line shown below (or you can use GUI of Nuget Package manager by Right Clicking on Root Project Solution and removing them).

   PM> Uninstall-package Microsoft.CodeDom.Providers.DotNetCompilerPlatform
   PM> Uninstall-package Microsoft.Net.Compilers
   

2. Remove the following code from your Web.Config file and restart IIS. (Use this method only if step 1 doesn't solve your problem.)

   <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>