Upgrading the web.config file to SharePoint 2013

In SharePoint 2010 if we have any of the custom CAS policy defined and which is also referred in web.config file, then on upgrading the site from 2010 to SharePoint 2013, that entry will be missing in the web.config file.

<TrustLevel node is not available in web.config by default in SP2013, we need to update the code to insert the additional node before adding the custom CAS policy.

Retrieve the web.config modifications

The following powerhsell script will retrieve the web.cofig modifications for sharepoint Web application.

Script:

$webApp = Get-SPWebApplication -Identity http://sharepointsite
$webApp.WebConfigModifications