---
agentTools:
  projectIndex: https://opencontent.readme.io/v3.2/llms.txt
---

# F.A.Q.

[block:api-header]
{
  "type": "basic",
  "title": "Errors after upgrade to DNN 8?"
}
[/block]

When  you get this error:

Could not load file or assembly 'System.Web.Helpers, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)

Make sure the following is present in the web.config

[block:code]
{
  "codes": [
    {
      "code": "<dependentAssembly>\n  <assemblyIdentity name=\"System.Web.Helpers\" publicKeyToken=\"31bf3856ad364e35\" />\n  <bindingRedirect oldVersion=\"1.0.0.0-3.0.0.0\" newVersion=\"3.0.0.0\" />\n</dependentAssembly>\n",
      "language": "xml"
    }
  ]
}
[/block]