Turn off Friendly Errors

Thanks to Heather Solomon

While in development, the friendly error page that SharePoint displays when your page has an error can make debugging your master page issues very difficult. You can make an easy change to your Web config file for the site to turn friendly error messages off, therefore providing you with more useful information if your page breaks. Only do the following in a development environment, you would never want to turn off friendly error messages in a production environment. Also be sure to make a back up of the file prior to editing.

1. On the Web server, navigate to the site directory:
   Local Drive:\Inetpub\wwwroot\wss\VirtualDirectories\[directory for site] (for example 84)
2. Open Web.config in Notepad.
3. Search for "CallStack". Change the CallStack status to "true".
   CallStack="true" DirectFileDependencies="10" TotalFileDependencies="50" AllowPageLevelTrace="false">
4. Search for "CustomErrors". Change the mode to "off".
   mode="Off" />
5. Save and close the file.

Now when your site encounters an error, you will receive a .NET screen outlining the issue instead of the friendly SharePoint error screen. This is particularly useful with dealing with missing Content Placeholders and editing Master Pages. To turn friendly error messages back on, just walk through these steps setting the CallStack to false and CustomErrors mode to On.