An error occurred creating the configuration section handler for system.web.webPages.razor/host: Could not load file or assembly 'System.Web.WebPages.Razor, Version=2.0.0.0

An error occurred creating the configuration section handler for system.web.webPages.razor/host: Could not load file or assembly 'System.Web.WebPages.Razor, Version=2.0.0.0, Culture=neutral

I have solved this problem by applying proper reference of System.Web.WebPages.Razor version in the web.config file of views folder. 

I have seen the version difference in global web.config and the views folder of web.config. Finally I referred the same version what is in the global.webconfig to the views folder of web.config. 

Here I change Version 2.0.0.0 to Version 3.0.0.0,

<configSections>
   <sectionGroup name="system.web.webPages.razor" type="System.Web.WebPages.Razor.Configuration.RazorWebSectionGroup,System.Web.WebPages.Razor, Version=3.0.0.0, Culture=neutral,PublicKeyToken=31BF3856AD364E35">
     <section name="host" type="System.Web.WebPages.Razor.Configuration.HostSection,System.Web.WebPages.Razor, Version=3.0.0.0, Culture=neutral,PublicKeyToken=31BF3856AD364E35" requirePermission="false" />
     <section name="pages" type="System.Web.WebPages.Razor.Configuration.RazorPagesSection,System.Web.WebPages.Razor, Version=3.0.0.0, Culture=neutral,PublicKeyToken=31BF3856AD364E35" requirePermission="false" />
   </sectionGroup>
</configSections>

Note:

These problems may happen when you are updating all of your packages. So that Views web.config requires the manual changes.