Weird Error Message:
Compilation Error
Description: An error occurred during the compilation of a resource required to service this request. Please review the following specific error details and modify your source code appropriately.
Compiler Error Message: CS0012: The type ‘System.Object’ is defined in an assembly that is not referenced. You must add a reference to assembly ‘System.Runtime, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a’.
Fix:
Put this Assembly-Reference in the web.config:
<compilation debug="true" targetFramework="4.5"><assemblies><add assembly="System.Runtime, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" /></assemblies></compilation>Reason:
This error occures when you are using Portable Class Libraries (PCLs) inside ASP.NET Projects. This Blogpost provides a pretty good answer. In short: It’s an issue between runtime and build time - PCLs that are used in Razor are runtime stuff.
I (re-)blogged this because I had this issue more than once ;)
Hope this helps!