Upgrade from MVC 4 to 5

Steps to upgrade

Follow the steps below to upgrade your Optimizely project to the latest MVC version.

Upgrade your site to the latest NuGet package for ASP.NET MVC, run "Update-Package Microsoft.AspNet.Mvc" in the Package Manager Console.
Update the application web.config file in your project as follows:
- Change the System.Web.Mvc version number from "4.0.0.0" to "5.0.0.0".
- Change the System.Web.Helpers and System.Web.WebPages version number from "2.0.0.0" to "3.0.0.0" (if not already done). If System.Web.WebPages.Razor exist as a dependent assembly it should also have version "3.0.0.0".
- Change the webpages:Version in the section from 2.0.0.0.0 to 3.0.0.0.
The result should look like:

<assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
            <dependentAssembly>
              <assemblyIdentity name="System.Web.Helpers" publicKeyToken="31bf3856ad364e35" />
              <bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0" />
            </dependentAssembly>
            <dependentAssembly>
              <assemblyIdentity name="System.Web.WebPages" publicKeyToken="31bf3856ad364e35" />
              <bindingRedirect oldVersion="0.0.0.0-3.0.0.0" newVersion="3.0.0.0" />
            </dependentAssembly>
            <dependentAssembly>
              <assemblyIdentity name="System.Web.WebPages.Razor" publicKeyToken="31bf3856ad364e35" />
              <bindingRedirect oldVersion="0.0.0.0-3.0.0.0" newVersion="3.0.0.0" />
            </dependentAssembly>
            <dependentAssembly>
              <assemblyIdentity name="System.Web.Mvc" publicKeyToken="31bf3856ad364e35" />
              <bindingRedirect oldVersion="0.0.0.0-5.2.3.0" newVersion="5.2.3.0" />
            </dependentAssembly>
          </assemblyBinding>
        </runtime>
          
          <appSettings>
            <add key="webpages:Version" value="3.0.0.0" />
            <add key="webpages:Enabled" value="false" />
            <add key="PreserveLoginUrl" value="true" />
            <add key="ClientValidationEnabled" value="true" />
            <add key="UnobtrusiveJavaScriptEnabled" value="true" />
          </appSettings>

Update the web.config file in the Views folder as follows:
- Update elements containing System.Web.Mvc from version "4.0.0.0" to "5.0.0.0".
- Update elements containing System.Web.WebPages.Razor from version "2.0.0.0" to "3.0.0.0".

<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>

  If this section contains **System.Web.WebPages**, update those elements from version "2.0.0.0" to "3.0.0.0".

<configuration>
          <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>

If you use Web API 1, run "Install-Package Microsoft.AspNet.WebApi.WebHost" in the Package Manager Console to update your global.asax from:
```
WebApiConfig.Register(GlobalConfiguration.Configuration);
```
to:
```
GlobalConfiguration.Configure(WebApiConfig.Register);
```
Build your solution and verify that the site is working.

Steps to upgrade

See also